Charging ahead: batteries of the future

Public lecture presented by Yi Cui



well thank you um it's always a great pleasure to give

a public lecture like this because the audience is not the order is usually a

professor will be giving talks to this indeed please send a great challenge for

Professor I actually got quite a bit of training in order to uh give a select

public lecture we have a great team right here in select National Lab uh but Michael in the team inviting me

to talk about batteries indeed if you look back about six years ago I gave a

public lecture like this topic I was thinking you know what's really new I can tell you or deeper things I can tell

you indeed in the past um six years

many great things happen well you see electrical car really took off right in

the big way globally so that's a quite a difference right there

and since last year I took on the director position for uh at The pre-core

Institute for energy this allowed me to look at broader

and the energy transformation uh going from fossil fuel to the clean

energy and with even bigger picture what the battery research what can it really

do to impact the society so let me share with you

this first slide and the big picture the global commitment to The Net Zero Net

Zero means a nasal carbon emission by a certain time frame 2050 is Paris

agreement in the U.S is was back to Paris agreement uh these are the major countries the

emitters contribute to the carbon they all committed by certain time uh time frame

and 60 percent of Fortune 500 companies also committed to climate goals

and if you look at this Global commitment energy industry contribute to

some somewhere more than 30 trillion dollars per year

and then looking at where CO2 carbon really come from these two sectors stand

out the most transportation electricity your electrical grid

if you could decarbonize these two you decarbonize

have a little bit more than half of the global economy already so it's

very very important of course other sectors are important as well industry by still making cement making Plastics

these are all important and Agriculture and the building as well

so and to decarbonize these two batteries actually play very important

role and on the top row is the application that's for portable

electrical Transportation right here and also airplanes we don't know how to

do that yet that's why you know people draw two batteries right there it's actually very challenging problem

potential batteries can impact and stationary energy storage to

integrate solar and wind electricity into the electrical grid this intermittent source

of energy electricity this is required to store the energy so it becomes very clear for the modern

society how important the batteries are but when I started 17 years ago as

Stanford I was the only person to work on batteries other than about 1970s we have

senior faculty in the department working on that he retired and then when I 25 in 2005 to launch a

program on battery I didn't know it was so important but nowadays it's

very very clear so let's look at you know what are you looking for for the batteries the

certain parameters you need to Define then you you know what these batteries are good that one are not so good what

are you looking for you are looking for first is how much energy do you store

for a given weight or given volume of the batteries measure using one hour

you you're familiar with kilowatt hour right this is a one hour

and per kilogram or per liter so one is probably magic the other is water magic

for your cell phone you probably don't care about the weight as much it's actually the volume if you are limited

for the car we are limited by both you care about both weight and volume

of course it's also important imagine using how how much per dollar dollar per

kilowatt hour if you have really battery size like store certain energy how much

do you pay lifetime psycho life

cell phone usually you do one charge per day electrical cut maybe you do a charge per

week or couple charges per week uh and then calendar live is how many years this will last

and they are correlated but they are not exactly the same some batteries can have

long cycle life but short calendar life if you just let it sit right there and

wait for a couple of years the battery could die even you don't use it

so charging way is important right we talk about now typically an hour or two

Tesla the uh the fast charge 30 minutes can get you probably about 60 to 80

percent uh if you do get a fast charging in their station

and then safety you care about safety Catching Fires explosion these are the

problems you care about so these are the basic parameters you ask first

and then now let's come back to what exactly how are we going to do innovation

you say well you hear about all kind of battery in the commonweized lithium-i and you heard about lead acid batteries

in the past you notice the nickel metal hydride this nickel cardamom this air

climb bandages all kind of chemistry what's really going on how do you choose why people develop this different set of

chemistry let's look at how you distort electrons first store this electricity well let's come back to very very simple

chemistry what you want to store is electron that's tiny e right there

but they have negative charge if you put two negative charge together they repair

each other and how do you put a lot of them stuck them together not possible

then you say let me balance the charge make it charge neutral you need to put

something that's positive positive trust that's ions

well this could be lithium ions it could be hydrogen ions as proton so to balance

discharge maintain charge neutral so you can store a lot of this together however

what you are paying the price is so big election is very lightweight but iron is

thousands of tons ten thousand times heavier so you are paying a lot to store that

electrons normally you're paying a lot by these ions you also need to have

electrons and ions to store I call it as a host let them all come in to meet get

stall this host can be also very very heavy very big you pay even more

in order to store the electrons I mean the whole game of innovation becomes hey

let's pay as little as possible let's play as little as possible to

store the electrons so what are the choices let's come come back to chemistry well let's first of all let's

use atomic weight I want to pick those very lightweight very small ions so I

pay less so the lightest one is proton it's hydrogen with atomic weight as one

once you use proton oftentimes that technology is called fuel cell technology hydrogen fuel cell

right you use proton for doing that and then if you use lithium-i and now atomic weight 7 is much more heavier but

that's the next plot on the best you can do that's lithium ion batteries then you

say well I want to pick sodium atomic weight 23.

that's a lot heavier that's your sodium ion batteries if you say I want to pick

lead that's really big very heavy one hey

that's your lead acid batteries you use in your car gasoline car to start the engine

that's your lead acid batteries the way you pay is just going high and higher these are all the research now batteries

exists zinc iron zinc metal aluminum magnesium these are all ongoing so

there's a lot of choices but lithium ion is favor and proton fields are in favor let's

look at this other reason other consideration we need to talk about and

what's the maximum voltage per battery cell you can have

what what decide that that's actually in chemistry this term called

electronegativity or Electro positivity the ability of this element they can

keep electrons or giving electrons that ability determined at the end what's the

voltage of your cell so lithium is the one they don't like lights on they like to

give electron a way so the potential is very low they don't want to keep electrons at all eventually you make a

battery cell this used as a negative Electro using lithium metal and then you have a a positive relaxation right there

you can build a high voltage cell up to roughly within this range 4.5

that's the highest one you can find that's why this is favor and you consume electronics and your cell phone because

you need to have high enough wattage to power your transistor power your

semiconductor chips having one cell you say why don't I use multiple cell

connecting in seals you could do that but you pay the penalty you need to pack so many it's not convenient the cost

will be very high so proton even though it's lightweight we know in water it's

limited by the water how stable that is if you put two electrode into the water

right you're going to spray water generally hydrogen usually it's about

1.5 usually so lithium is favor in this case

but when you look at the cause lithium is the highest one right proton from

water is nearly free if you are charged back and forth It's really nearly free

so from the core standpoint lithium is not so good but lithium so far probably occupy the

the battery called my back is about 10 in the past it's less than three percent in the past two three years lithium

price goes Skyrocket and it occupied bigger percentage of the cost right now

so with this consideration and there's a reason why at least in my mouth is dominating it's offering you

this very light element even though it's not as light as hydrogen but it's the next lightest one you can

find least in mind can move very fast um so if you take these material you say

well let's look at the real battery itself right this is typical cylinder cell the size I put it right here is called

18 6 8650 is 80 millimeter in diameter

here 65 millimeter in height this is the

cell Tesla packs 7 000 of these batteries together put into the Tesla

car at the beginning now Tesla go to slightly bigger cell right now but the

idea is similar if you cut it open you're going to see this multi-layer of

this metallic foil a copper foil aluminum foil it comes with materials

it's a polymer layer this blue color is a porous polymer as a separator

simply hope electrical from aluminum electrode prevents shorting and roll

together if you zoom in further just look at this cross section on on top of

copper there is a layer of materials right here this is graphite

graphite is the host materials to host electrons and leave them together to

every six carbon when you do the battery charging electrons and lithium all go to this

graphite particle and get stored right there when you do discharge election will return to the this side and the

lithium will return to this side and forming this lithium carbon oxide oh actually these two materials are the

bases for the initial lithium-ion battery commercialization this is also the

important materials 2019 Nobel Prize was given to lithium-ion batteries and using

the invention of this type of material will really enable that oh and also by the way you happen to sit in this week

for this lecture this is the week of Nobel week since Monday until today you see one Nobel Prize announcement day by

day um so in order to have this all work out you know inside here you see the

separator Legion shuttle back and forth electron coming back and forth during charging discharging

and the fundamental thinking is how you got to move the electrons Elation needs

to be able to travel for one electrode to the other electrode and then go into this particle during charging and

lithium should be able to move from right hand side to the left hand side insert it into this particle

will meet right there right so these are the two basic process got to be

happening you say well isn't that really easy no it's not easy at all for some materials because if you look at

graphite that's easy because graph is very conducting lithium carbon oxide is reasonable also quite conducting but for

some of the exciting materials you want to produce for the Battery Technology they are not

necessarily that conducting you need to understand why they are not conducting how do you make them conducting

and then through this process because lithium relation coming in and out they have volume they have size

they're going to cause strong structural change they're going to cause this particle breathing you know become

bigger smaller during charging discharging this all happen at the same time not only that each of these

particles particularly on the end of the negative Electro side graphite which the

electrons write a very reactive this electron will likely react with this

electrolyte liquid electrolyte soak into these batteries and generally a cell

decomposition compound is particles surface coated by a layer of very very thin coating that is called

solid electrolyte interface we also call it SCI this interface is the gate for

lithium ion going in and coming out this lays very very important if this layer

breaks then electron can leak out well with more electrolyte if this layer

doesn't conduct lithium that much make it harder for lithium to go in it's very

hard for you to charge and discharge your battery so this layer is very very important

so looking at where we are right now all right and those parameters we are

roughly about 250 one hour per kilogram can we double that

gets high and higher energy density we are roughly about 130 dollars per

kilowatt hour in the cell level can we reduce that by multiple times so then

the electrical car will be much cheaper so far the battery pack occupy really big fraction of the cost

and a thousand cycle seven years can we go to ten thousand Cycles 30 years

one to two hours charging usually can we do within 10 minutes very fast charging

then it's almost similar as you know go to the gas station adding gasoline right

that's a few minutes type of feeling and from not safe to completely safe

well these are the questions we want to answer these are the Technologies we would like to develop of

course it's very hard to have everything all together within one technology I

would say if you can make certain parameters reasonable you can improve one parameters in a dramatic way that's

already a breakthrough for the Battery Technology so in today's topic we start

introduction let me share with you these questions I want to provide some answers

to you is how high energy can we go

with the existing uh you know chemistry now

how do we really understand what happened inside the battery I want to present to you a new tool

that can get you to the the level never you've never seen before

and help you to extend the battery life help you to understand the battery safety that's quite electron microscopy

and we have a national facility right here at slang National Lab very powerful

too benefit safety everybody care about I'm going to touch upon that and also risk

energy storage how do you store solar in winning electricity really bad big battery Farm what's the technology

available for you to do that and eventually let's come down come to

the last topic scaling a circular economy because the the whole world is going through Global clean energy

transformation we need to store a lot of clean electricity and the battery pack will be big battery Farm will be big can

we really get there with the resources we have so let's look at the high energy density

one this is where we are right now if we can double

this huge meaning right the driving range of the the battery car roughly

double if we can go to four times of the content not built a one thousand mile

per kilo and the next time I go to Boston I probably will be taking electrical plane

right so this is the impact you can imagine we might have so high energy

dense is very important so how do you increase the energy you store energy e

right here right this is the high school physics equals to voltage multiplied by

charge the skill you want a high voltage batteries you want to stop as as many charges as

possible so that is what you need high voltage store

a lot of charge and you want the lightweight the host material to be lightweight and uh and the volume needs to be small

then you can have high energy density so this is used in the current

Technologies this graphite graphite using Android Lithium-ion batteries this

is uh this carbon atom forming covalent bonding right here this is so-called

graphene layer and this layer stacked together forming graphite right and

lithium coming in still between the graphene layer hiding between the space giving you

these 370 milliamp hour program so battery field has this very strange unit

now not traditional but it's very convenient to use milliamp is current

hour is time current times time if you charge so that's the unit we we use a lot

um but Futures so it is typo right here future and nodes

um silicon can store a lot more 4200 metallic lithium still also very high

so if you can make these two work you can store 10 times of the

current technology so that's very attractive to work on new materials silicon and metallism

on the castle side lithium carbon oxide lithium manganese oxide lithium ion phosphate this this amount of charge

let's say close to the neighborhood of 200 million miles per gram right this has been the power really this has been

a very important material really power your devices you know lithium and phosphate is using electrical a lot

lithium carbon oxide is using your cell phone and the variational lithium carbon oxide now is used a lot in your

electrical car so what if you can make something like sulfur

that could work this offer this gigantic charges stories capacity which is about

also 10 times of use of existing technology and also by the way software

is so low cost it's so abundant this transition metal right here

Cobalt's cause will be too high when you go to scale and you need to think about abundant

material low-cost materials so can we make these new materials to work if we

could this pathway might be possible going from current technology or 251 per

kilo which is a nickel manganese copper oxide right graphite and no MMC this is

MMC if silicon coming in pair with MMS you can get a 400 maybe slightly higher

metallic lithium coming in 500 lithium metal sulfur can we enable 600 to a thousand

while per gallo before my retirement I really like to

take electrical plane from West Coast to the east coast right that's a gym before I retire Michael I still have some time

so so but what are the problems why we

couldn't use those new materials It's really because there's still so

many lithium ions compared to traditional material traditional material hosts they're stable in the

past 30 years we have been using that like Wi-Fi lithium carbon oxide they don't store

them that much lithium they're stable the new materials coming in lithium

coming in right into this new material or just putting all this chemical bonding I go that's crazy when you break these

house materials and then these host atoms silicon just moving around leave it

moving around completely crazy and complete structure change gigantic

volume expansion in the past the old materials all less than 10 percent volume expansion once you have lithium

coming in the new material will go to 100 percent and you could even go higher 400 percent

so much more expansion you need to overcome how do we do that I mean that's

completely crazy to think about it so 2005 I joined in as a faculty it's

good to be a young faculty you are not afraid of anything that's why you want to hire young people into your group because they come in they don't know

enough yet yeah so they say I can do make anything happen I I really need to

have high school still and to get into the field very very soon they're not afraid of anything right that's the best

if you are not afraid of anything the possibilities there to solve the

problem if you're getting to you know too much later in your career you say I've seen

these discussion work that doesn't work so it really doesn't work if you think this way

so silicon let's come back to Silicon silicon can store so much lithium and

because one silicon atom can combine with 4.4 lithium ions six carbon can

only combine with one lithium so some can still store a lot more but

because it's not so much more the one expansion of single silicon particle you put lithium in one expansion to four

times roll it up they're going to break once they break this particle pieces the dead

body they're not connected with each other you cannot get electrons in anymore right you really cannot remember

I told you the first requirement is make sure electrodes can go in if they lose

contact they are not going to be able to go in the Bears will die

the second thing is what is solid electron interface SCI let me emphasize

this parameter again you need to form a stable layer on the surface if this

volume expansion is happening how could you form a stable layer particularly if silicon is breaking

there's no way so the surface of silicon will continue to react is soaked into the liquid

electrolyte continuously react with liquid Electra like decomposed electrolyte the batteries also die fast

because your electric light will dry out you consume lithium so back in 2018 January we published the

first paper that was about two and a half years after joining faculty this was my first batch of graduate student

she's a faculty member at Southern State right now we use this silicon nanowise

structure diameter is very small and and grow this while the bottom they

are in contact with this metallic foil column collector now you can shoot electrons in and out

this is continuous pathway and then you can relax The Strain because volume expansion take place it can break but

once you make it small enough they don't break anymore the pop is the first paper turned out to be this is a paper get me 10U here at

Stanford so this is the paper really you know set the button of starting the whole research field or nano technology

for batteries so it's good to be not afraid of the uh the old problem

um I collably with my colleague Professor Bill Nix a mechanical expert Matt was my early graduate student now a

faculty member in Georgia attack we said let's go to see what happened in this material let's develop a tool we

can see this this is a holder we call it a holder you can insert into

transmission electron microscope then you it transmission electron Microsoft

can have this ability can see your structure down to atomic scale

so if you zoom in right here this is a single nanowire we can connect with a

gold Pro a tiny tip and this lithium carbon oxide that's castle that's anal this ionic liquid

with a lithium salt in there you're building a nanoscale batteries inside electromicoscope then you can charge it

up to see what happened so we can also smartly put some particle right there we can watch the particles as well let me

share with you using a tool like this we can first time visualize you know how the volume expansion take

place how this material will be broken if they're too big so this is a a movie

this is 200 nanometer this is roughly close to about a

thousand times smaller than your hair close to a thousand times

this is 200 nanometer diameter once you put lithium in you see this uh silicon yellow and volume expansion take place

and this silicon White surface is coded by copper

material they are broken by silicon wire this expansion is so powerful you just

cannot stop it and then now let's look at another video These have some silicon particle

attached to the wire this this is also 200 nanometer this one is smaller this

one will be big it's a much bigger one this is 800 nanometer in diameter you're

going to see this big particle just grow bigger and bigger and you see this

interface right here this is a question called This is a morph it's lithium silicon aeroid eventually this particle

just accumulate huge stress it will not be able to you know contain

the stress anymore it's going to be broken once in place

and you lose capacity you lose really a lot of little silicon so we need to

identify what's the critical breaking size how small do you need to make this

structure so they don't break anymore so why small structures will not play because you keep breaking things into

smaller and smaller they've got to be a limit if you are smaller than the smallest structure that lithium can play

they don't blade anymore that's the reason so over the years using wires

and we learn so much I'm not going to bother you the 12th generation of

material design we try to solve interfacial stability problem with today's for today's purpose I will not

be able to go into the detail but let me share with you this is a tough job this is over 15 years of research 12th

generation I'm a little bit of superstitious like I was talking is a good number if I want to do something I

stop at 12 or 9 or 8 or 6 I will not stop at the 13. so this is 12th

generation that's it so all done um so back in 2008

uh when we published silicon noi paper I was contacted by this is Sun Hill Road

all the money are sitting right here right across the street from slack right people come talk come to my office to

talk to me about starting our company I wasn't ready but you know once you talk to people

everybody keeps telling you the same message you kind of start to believe in it

so I start to believe in this and say oh maybe I should start our company so which I did so in 2008 I founded the

empress over what this is now 14 years and

Empress has been doing a great job I think I was also lucky as well I didn't know how hard that was it was good to be

very young right you are not afraid of a failure you just say hey let's do it just go in and do it so MP is producing

very high energy density or bare face right now shipping to a customer uh it's very exciting

a couple of weeks ago amp is actually went for IPO uh but it's a very tough

time to be an IBO market right so Empress went ahead and do it so we went to New York to win the bear and this is

the whole board and also the amazing team I need to say congratulations to the

empress team it's the hard work to make this happen um but what's the lessons I learned

through this process for labs to Market so let me share with you this is the

lessons I learned first of all it's very very hard it costs a lot of money

uh Venture capitalists put in the money but what I learned from 2007 went into

technology was eventually published 2008 January until now

left to Market so what's the bridge you are really Crossing during this process

why it took 14 years so you have to understand in our lab we

are working on this milligram of materials what's milligram right 10 to minus 3 gram or material a tiny amount

and to go to commercial scale you need to go to time scale and then to occupy

big Market you have million times so many orders of magnitude of

difference you know 13 to 15 orders of manage your difference right there and we usually work on the area of

centimeter Square tiny area right to go to commercial scale you go

to meter Square thousand meters square and then a billion meter Square hi many other Humanity also

and also in the lab we we work on this concept this button cell tiny by

centimeter Square any commercial product this is like right you know like this

size regular phone size benefits if you go to electrical transportation that will be much bigger so from Lab

prototype commercial prototype and Manufacturing product right here there's so many technical risks

manufacturing risk what happened right there so this together is all the humanity you

need to cross so this will require you to have a long-term patient long-term support

going from fundamental and applied research to engineering to scale production so luckily in the valley

of the Stanford we have slang National Lab right here very strong fundamental basis across the street Sun Hill right

here there's a Rental Capital money right there you know in the whole village is a lot of talent it's all

co-located right here and to make this happen so not easy

so this first topic I want to share with you now let's look at the second one

well you know let's loot it back to the fundamental research why this is

important you know throughout my battery research I want to find out what happened inside the battery cell

if for most of you you say well you don't do battery research you say battery looks very simple right one

Electro is a reduction reaction the other is oxidation you write down the equation that said

but it's actually very very challenging to understand what happened inside for example

in the bathroom materials are very fragile if you want to go to atomic

scale resolution in order to understand how battery fail would you be able to do

it it also microscopy transmission electron microscopy is a golden tool to see atoms

so I really want to see atoms this is a metallic lithium forming this filamental

structure if you want to zoom in to obtain atomic scale resolution we are

destroying this sample very fast they're not stable

so and it's very very hard this is the reason is you focus the Electron Beam to

look at your your materials there's so much energy dumping onto these materials

it's like having a magnifier right to uh to burn the leaves or burn the ants you

know kids like to do because you focus the sunlight energy right there so we

need a tool for doing that and in 2019

uh so 2017 Nobel Prize was given to uh

these three gentlemen developing cryogenic electromicroscopy this is cryo

em for biology they can study the protein structure

and now we pay we notice this uh technique it's so powerful and staff is

like right here we hire one of the best quite acquire em expert in the world

Professor watu he joining right here to set up a national Center for elect for

cryogenic electromicroscopy I was learning from his research I said well

perhaps I can borrow this tool to study the battery materials because you can

freeze your sample with liquid nitrogen by the way liquid nitrogen is very very

cold I think some of you might be doing experiment before using liquid nitrogen to make ice cream right that tastes

really good that tastes really good but it's very very cold you can stabilize your sample and it's also how do you use

low dose Imaging low dose means hey let's don't use so many Lush and just use very small number of electrons to

look at your sample you can already get the image so you don't destroy your your materials and there's also Imaging

processing and so on so back in 2016 to 2017 I have two of my graduate students

and also by the way we often made fun of these two I say you guys last name is Li that's lithium so to work on lithium

battery so that's a good pair right to to work on this problem so two of them

develop this technique and how do you freeze your sample into liquid nitrogen

very fast and without changing your sample right and then while maintaining very cold

temperature close to liquidation temperature and chance for the sample at

the tip right here insert it into gigantic electron microscope without

exposing air so they did a good job on that and uh and using this technique for

the first time back in 2017 we were able to see this is atomic

atoms of lithiums for this metallic lithium structure for the first time everybody wants to see

that for the past 50 years right because the problem I mentioned to you electron just coming in Destroy This this sample

you will not be able to see it now first time we can image that not only that a

two like this allow us to answer questions for Boston 30 40 years now remember I keep telling you about the

solid electrolyte interface that really thin little coating on your graphite

particle right silicon surface also have that as well you know what's the atomic

structure of that layer nobody know and there are two hypotheses one say

well on this uh end of surface this thin layer of coating only about maybe about

20 nanometer only but really really thin it's a mosaic model you know it's this

tiny particle lithium oxide lithium fluoride and other things forming this past Mosaic patterns proposed by some

scientists listen this paper and it is another model structure model

thing is a layer model you have a layer of inorganics on top of that a layer of this Organics

right there forming the bilayers well you might ask the question you say who cares you know what's the structure oh

you do care we actually find out these two different structures will be very different

and affecting your battery charging discharging efficiency the battery life

so using this Quail em Technique we develop we were able to resolve your

synthesis lithium method this is interface this this interfacial layer right there this beautiful inorganic

particle embedded into this green highlight as a green Organics in there this is more like

Mosaic type of model this is under one of the type of organic electrolyte you

know and the whole battery industry each company have the secret electrolyte they will add in some school additive it's

like cooking right you add a little bit of salt add a little bit of pepper you might add

a little bit of secret sauce made your dish taste better nobody knows what you add in that's what the battery industry

has been doing so if you add in a secret sauce containing fluorine right here right I mean this interfacial layer

change this Green Layer on top has this beautiful inorganic lithium oxide coating turn out

to be these solid larger interface this structure give you much better battery performance

compared to the previous one so we are establishing now this correlation of

performance with um uh with the structure

so now let me come to the battery safety this is often very exciting because you

got to see some fire burning right there so and every time talking about safety

this all come up right whether it's from the laptop the phone the car now this is

stationary storage and uh and this keep keeps happening so what's the reason

why lithium my Ambassador keep having fires well the biggest reason is that organic

electrolyte right there is organic that can be burned but how do you make it burn

so this is a bad phase like cancel and end or two elective is a separate for whatever reason happened right here

you cause a shouting there's something going on May your character and not

touch each other will leak electrons through that this will heat up your batteries this

reason might be due to hey you have manufacturing defect yourself it has a floor right there this might be due to

you to over charging that's why you're charging the control system needs to be

really good if you overcharge your batteries you can form this so-called lithium

dendrite for shorting then you or you can also have accident your cell crash

so once you have the shorting this will release a lot of current right a lot of

energy that is many fundamental process taking place without going to the detail you know this just start to heat up

eventually this will start to catch fire and explode

um so how do we solve this problem number one is prevent shorting detect the shouting before it happens

now let me present to you some of the ideas very quickly first idea is um

um there's something going on it is supposed not to be here

um so we invented smart separator this is a Catherine and now the regular

battery separate right here if you have shorting touching these two electrode you'll release energy

you know the better catch fire but can we put something in the middle and the separator if this goes halfway

we can detect it so we invented a new

technology that can detect half shells uh apologize for for this figure and we

also invented another technology we say well what if the shorting really happened it starts to heat up but we

don't want it to be heat up too much we develop a layout coating onto this

current collector that's colon collector and if you zoom in inside this is a

polymer layer with this metallic Nano spy you see spiky thing right there at

room temperature they are conducting if your battery cell heats up this polymer volume expands they're going to expand

will pull this particle open they don't touch each other anymore and this whole thing becomes insulated this becomes a

protecting switch we show that this could protect your batteries from capturing fire

the most recent one is very exciting is come back to the structure again this metallic foil only used in the past

only during the function of you know coding the graphite particle in there doing charging getting the electricity

in taking the electricity out I mean it's not really that smart like only doing this I would say the dumb job

right so why don't we utilize this current collector we've invented a

Twilight coloring collector we put a polymer right here that's polyamide and

embedded TPP molecule this is a fire extinguished molecules into this

polyami and cultivist copper these are still conducting we invent a new type of

a current collector once this battery about to catch fire this poly inmate

will release PPP extinguish the fire let me share with you this video the left

hand side is the regular copper foil column collector made into the battery the right hand side is our triple layer

colon collector let's look at the video now you build a bearfish now you want to

use the fire and try to burn it you're good to see the left hand side it's going to catch fire and continue

burning now let's look at the right hand side

you try to burn it it's actually first of all it's much harder to ignite

the right hand side because the release of TPP even you can burn it and it's going to

sell extinguish after several seconds so the right hand

side is much safer we are hoping to have such a technology to go into the real world very soon to uh enhance the

battery safety so the remaining of minutes let me not share with you a very exciting topic on

Whiskey energy stories this has been a problem we've been thinking about try to

invent a new technology for a long time it's it's indeed very very hard the reason is to go to brisket it's a

gigantic storage unit right there and then the grids require you to go to

smooth out the green made the electrical very stable for minutes to minute energy storage from hour to hour day-to-day

week-to-week month to month seasonal eventually for example in the summer time you generate a lot of

solar electricity but winter time you don't have that much then you need to store the Summer Electricity wait until

winter and then release it so every year you only use that battery for one to two

cycles then the discovery course got to be really low right so far we are 130

dollars per kilowatt hour eventually we need to go below this number we don't know how to do it

and we don't even know how to do day-to-day that well by now we probably know how to do four hours

and also you want very long life you invest such a big you know a battery

Farm if you only use for 10 years now economy is not good you really want it

30 years or longer one day per cycle it requires 11 000 cycle if you want to do

three cycle per day it's going to be 30 000 Cycles or longer

you need very long cycle life batteries right there you want it to be maintenance free at all climates solar

is usually in a very hot weather right wind is very cold lithium ion battery

will not do well I think I believe some most of you have been skiing and like Tahoe

take yourself and with you and see what happened automatically turn off it's too cold the cell phone will not work

anymore it's because of batteries right there so extreme heat and cold can you invent

a biopsy can do that needs to be very safe so well five years ago we look into this

problem he say well what's the longest lifetime battery Capital chemistry ever

invented in human history what's the longest life end of chemistry ever invented in chemistry let's marry these

two together if they have not seen each other yet let's Force the marriage and see whether that can happen

will turn out to be nickel hydroxide become nickel oxyhydroxide is the

longest lifetime cathode chemistry one of them one of the few ever invented

for the annual side is water become hydrogen hydrogen become water that's the longest lifetime

so I was talking to my students poster I say hey let's Force this tool to get married

to produce you write the equation it's beautiful you know balanced equation that sounds like it should work so it

did work so we produce this material this is a tank this is the kind of the

Rolling similar as the cylinder cell I tell you before if you zoom in this is the capital separator right here this is

your handle which is catalyst to catalyze hydrogen become water

well when we invented this I was very excited but turned out to be no I was not the first one

and 30 40 years ago in aviation industry NASA has been using this chemistry

for Harbor telescope for 30 years now I just didn't know about it

but NASA's version was too expensive they use platinum as the Catalyst right

here our contribution is put down very low cost calculator replace Platinum now it

can be for a civilian use so we made this Excel and we show this

can last forever this is ten thousand cycle after that you still have 95 capacity retention

this can go more more than 30 000 cycle more than 30 years this is again a tiny

cell we do in the left centimeter square a type of level right and we will need to go bigger to go to uh the real world

and not only that we notice nickel the price is not the lowest one we have

manganese lead and iron this much much lower cost come back to the very early

style I was telling you installing energy is about finding

that uh you know a metal ion can balance the charge and we we care about the

cause for the very big system so you look at this manganese of low cost we actually invented for the first

time or manganese hydrogen gas batteries here is a manganese two plus can become

manganese dioxide back and forth this is hydrogen become proton back and forth this is overall reaction without going

for detail well this is a chemistry really worth looking at for for the long

term this is going to join a very low cost balance chemistry so with this invention this family of

using metal with hydrogen two and a half years ago I spent now in the vanilla

company the building this gigantic battery cell with four inch diameter one

foot tall and really showing these amazing performance zero accidents can store energy across

multiple hours zero maintenance can go down to very low temperature very high temperature

and and you know what in a van you just shift the first product out to customer about months ago and just announced a

purchase order from a major green Energy company of 250 megawatt hour

so I'm so happy to see this is a shipping container going out uh so this

is coming up big now talking about big the last topic is

very important let's let's imagine how big is Big right

this whole this whole Market how much do you need uh let me give you some number this is a

portable applications I roughly estimate we need about 100

kilowatt hour for this mobile applications for stationary was roughly need 200 in order

to go to carbon neutral transformation going to Net Zero total is about 300

kilowatt hour well what does this mean 300 kilowatt hour let me give you a calibration

lithium ion batteries has been commercialized for 30 more than 30 years

now so aggressive building in the past decade now if you come a column

production also count announcement people say they're going to build the

plan to produce Lithium-ion batteries they haven't built yet condos in

pays about one terawatt hour per year we need 300 kilowatt hour how many years do

we need to produce this 300 years we we don't have 300 years to do it

so how much materials how big are these battery pack 300 kilowatt hour roughly

in the Pack level is about 3 billion ton of batteries well

what's three billion ton let's also calibrate ourselves anybody can have a unit to calibrate what's 3 billion ton

right there we have about 7.5 billion people in the world having all the people's way

together let's take a guess what's the weight this is my colleague that would like to

use to calibrate people say billion times what does it mean it's only about 0.5

billion tons of human being the whole world adding together this is much more

heavier so how much material do we need to produce these are the challenges we need to face

scale production in order to produce this 300 kilowatt hour

and we need to scale up 10 to 30 terawatt hour production so the whole world production need to go

10 times 30 times more and we don't have enough materials for

doing that we need lithium we need copper we need nickel copper manganese we need a lot of

stuff we also need graduate steel that we need high school we need undergrad all coming

in right this is this huge industry coming up and then we need recycling

and we cannot afford to just bury these berries anymore got to be recycled circular economy I don't have a good

answer for doing that but we will need to do that for sure

so with this presenting this biggest challenge I know this is high school student right here you have 60 years

ahead of you so you got time let's look at the summary uh I was

presenting to you the future of the Beatrice how high energy can we go to

possibly I believe we can get to 500 watt per kilo maybe we'll get to a thousand by the

time I retire and we need tools to understand what happened inside the

battery so we can make better batteries we need National Lab we need University

to work together we need long-term investment from the government to do so

the battery safety we need Innovative approach to completely solve that problem for the lithium ion otherwise we

all need to go to aqueous chemistry it's much safer that is really the case for

this nickel hydrogen magnetization a gas battery use Koh solution is aqueous

solution based solution based chemistry scaling a circle economy remember the

number I give to you 300 terawatt hour that's the number we got to think about

for the next 30 Years Mr let me end my talk by thanking uh all

my students and postdocs I have very talented pool of students I think two

three of them are sitting right here right now you have questions they can answer the questions they are the hero

doing all the nice work and the funding agency from particular Department energy

um slag National Lab is a doe lab theory has been supporting National Labs

supporting University Research for very long term this will continue going

we start our stop I will be happy to ask any questions you have particularly from the very young students right here thank

you very much

so you thank you very much it's a really Visionary talk

and we do have time for questions I apologize to those people who are viewing us remotely the questions will

be just from people in this room so here's the deal raise your hand if you have a question

the thing in front of you is a microphone just to tap the little button in front of you when I call on you to

speak it'll uh the microphone will turn red and you're on please two people

don't use the microphone at the same time it gets confusing so who would like to ask a question

okay it's one all the way at the back ah please okay thank you very much I picked

me first to ask a question yeah a couple days ago just read the article that mentioned about the metal hazards is

very hard to transport because the unstable and now you just mentioned that I think on one slide and there's a

company give the solution is that right to transport metal hydrogen

oh um if I understand your question why it's really about transporting hydrogen

that's hard um so this metal hydrogen batteries when

they are made there's no hydrogen in them yeah it's all water then when you build a batteries you know

put in the pack right there in a stationary store is the first time you use it you charge it up the hydrogen

starts to show up uh that's probably what you refer to is transport hydrogen

is very hard but we are not transporting the hydrogen we are transferring the batteries

without hydrogen in it because it is in the discharge state okay thank you yeah

next please yes hi professor great uh great great talk

thank you it's really stimulating um for your dream of flying to Boston which

doesn't really sound like a great dream to be honest I mean we

um what is it what's the energy density of something like kerosene compared to the

battery energy densities you talk about Target a thousand watt hour kilograms how does that compare with hydrocarbons

hydrocarbon is much higher that's for sure much much higher um but you can see the hydrocarbon alone

that's much higher but once you compare the whole system you need to burn

hydrocarbon you need to deal with all the exhaust eventually hydrocarbons

still much higher the whole system level that's why you are more looking into high 2000 watts per kilo you know 2 500

watts per kilo for the whole system level or hydrocarbon for the benefit one

if you can get to A Thousand Mile per kilogram of energy density and the

continent airplane it's possible but the long distance

caused the ocean one will still be too high and this is not sufficient

so now you ask the question why don't why do we care about the battery so far

away so this short distance one will happen first for the for the airplane for the long distance one this

alternative solution I don't mean battery will be the solution for the long distance one and stand for right

here I can see the renewable field will be the approach

for the airplane that has a much higher chance to get to uh its carbon neutral

but still can do long distance so we might we need multi-approach going right

now uh for me I would just love to push the limit and see how far I can go for the batteries oh by the way I work on

renewable field as well so as a backup you see maybe you can fly to San Diego

in an electric plane that's that's I think that's possible yeah

okay please yes hi professor um

sorry I have a really limited knowledge of batteries so if I say anything don't

worry but um completely fine I'm sorry I remember you mentioning

um that batteries um they have like a hard time resisting

extreme weather uh extreme temperatures like cold or or hot so what is if if

there are some possible ways what are some ways that they would be able to

resist that yeah that's a good question um the lithium ions uh if you go to two

cold temperatures my battery has this organic electrolyte right because of low temperature it becomes viscous events

you can get Frozen once you get Frozen it doesn't work and even if it doesn't get Frozen if

it's too whiskers lithium ion can not move fast enough that also doesn't work if you go to

higher temperature and higher temperature and you know this

organic solvent have certain vapor pressure start to become Vapor not maybe

before that is a side chemical reaction starts to kick in between the organic electrolyte and your care so this very

complex chemical pathway will limit this also high temperature range of course

then you say why don't we invent new type of solve an electrolyte to solve that problem actually that's an exciting

research Direction many scientists are doing that uh that's all legitimate so

far we haven't got there yet but it's some promising data showing a particular low temperature one

I see there's some good stuff high temperature but also some good stuff but having both low and high temperature all

together is much harder that's an active Direction maybe you are in high school right now

uh that that could be something you should think about

another uh someone else please in front yes you

oh thank you very much um a Mr tree I have a question and I think several countries now they focus

on the Breakthrough of nuclear fusion reaction Technologies and I think that's

probably the ultimate technology to produce uh endless clean new energy and

of course and your lecture here today is mainly focus on a chemistry technology

new materials and no matter what in the future still need the new material to

hold the reaction of that nuclear fusion reaction I think that's probably also going to be a bottleneck so I want to

ask what's your vision about this two technologies I mean chemistry and also physics

to like a human being get like almost a free and clean and endless and the fiber

um clear energy thank you amazing question so today I

only talk about batteries I have another set of slides put down my director had as a prequel Institute for energy

I have a wish list top 10 technology we need nuclear fusion is one of them but I

don't work on Fusion but I recognize so important if we can get Fusion to work amazing so Fusion every time I talk to

my colleague Steve chubby always say it's 30 years away maybe now it's 25 years away but somewhere close to 30

years away highly supported people should work on future let's do that you know we can create

another sun right so artificial sun that would be amazing so this top 10 technology these other

things takes longer conversation I can share but I do have that slight India just gave a talk in the afternoon in San

Francisco just mentioned that so that's a simple version of answer to you that doesn't mean batteries will do will

solve everything no benefit will not be able to do that and we need many other

technology coming in I have my top 10 list yeah okay thank you Professor tree yeah okay there was one more question

here yes please uh good talk and especially on safety my

questions that you have shown all the M3 on the safety did you get a chance to look at

the various uh toxicity components and coming out of that and also my second

question is that at the end of life of any of these Technologies how do you handle recycling because you

cannot recycle 100 percent yeah um so the uh the file uh indeed when we

picked that TPP molecules and there's a number of choices you could have for the fire extinguisher we

are picking the one that's most environmental friendly I agree with you this other very nasty fire extinguisher

TPP is considered relatively same but I wouldn't say I

fully understand its environmental impact yet so I don't because this phosphate right there if it's the

burning is complete it's phosphate seems to be good if we cause some others

compound and this requires you to study I I'm not act completely expert on that

and then you mentioned the recycling and so far the two type of recycling

method is the dry method you know you're kind of burning Organics away you know burn as much as you can the prior

process as well consider a lot of energy otherwise the web process requires acid or base oftentimes it's acid so those

has a high environmental footprint so I would say people need to have the whole

circular thinking everything they put in everything comes out the gut developed a degree not polluting

the environment so I personally don't work in that area but I will encourage people to look at that carefully and

there's many a startup companies now and in the nation to to work on those problems and I think sooner or later the

uh the circular requirement will need people to reach the

deploy all the technology needed to get to the fully circular uh uh I believe we

do have the technology right there and it's just a matter of deployed and what's the cost

so last question I think sir so you've talked mostly I

uh the grid scale storage so your examples are all sort of chemical

storage mechanisms how would you say that compares to other forms of storage mechanical gravity

other ways to store large amounts of energy that's not sort of chemical so um

the storage Great scale having a different time the requirement minutes to manage

you know how to hour the technology could be very different minute to minute will favor the technology having

virtually infinite number of cycle life but can do this very fast uh back and

forth so that's why flywheel is used sometimes right and simple capacitors could be used that

hour to hours flywheel will be challenging and silver capacitor will be

challenging then the battery will start to kick in and then once you go to day to day probably stay in the battery domain

three days a week I believe about within a week it's probably better it will be

raining then you say going beyond that what's that then the chemical field might start to kick in hydrogen

by month to month storage and it is also Palm hydro pump height is always good

it's just how do you get permit and the total capacity remember we need

300 kilowatt hour I don't think we have that capacity and if you have your sofa

is probably about the global so far is about one kilowatt hour of

storage that's it after so many years of 100 Years of accumulation

uh what's the you know additional capacity you can do you can do gigawatt

hour many gigabyte getting another tele hour might be hard and you say what is also gravity I

respect that you know raising up and down and it all comes down to the cost

at the end maybe my personal opinion is biased because I work on batteries so I

I was just within a week it's probably is the belt is winning it and it's well

it is more than you know metal molten salt can come up to play a role it's all

about the cost so I need to wait and see their course can really get down to I'm looking for the storage solution per

kilowatt hour per cycle is one cent for the long term so let's see what channels

you can get there right and so for all those terminals are still too high cost

okay well thank you very very much for this inspiring lecture thank you

so uh professor schwe and his students will be around for a while out in the hall

so uh please uh we'll meet you in the hall outside this room and we'll those

of you have more questions we can sit around and discuss for a little while so thank you all for coming these

lectures continue probably the next one around Thanksgiving please see the announcement and um lots more

interesting things happen here so I hope you'll come back and hear about them


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