Breakthrough in Battery Technologies Nitash Balsara John Newman Venkat Srinivasan BATT Program LBNL

Summary of battery energy John Newman, my mentor

BATT snapshot Lithium batteries for transportation Electrolyte: Liquid organic solvents Polymers Gels Ionic liquids Cathode: Transition-metal oxides Spinel-based Olivine-based Anode: Carbon-based Alloys and intermetallics Oxides Lithium-metal Lithium batteries for transportation

Lithium-ion battery story Beginning of electronics… Bell Labs announced the discovery of the transistor in 1947. Start-ups like Fairchild and Intel beat giants like GE and RCA in electronics manufacturing. License for personal electronic devices sold to Ibuka and Morita for $25,000. gas tubes - to - solid state Sony introduces a game-changing wireless device (pocket transistor) in 1957. Sony recognizes the importance of powering electronic circuits (rather than the importance of Moore’s law) and introduced the lithium-ion cell in 1990. Every handheld device in the world today has a lithium-ion battery. None of the batteries are made outside Asia. …affects batteries transistor radio – to – lithium battery 4

History of battery specific energy ? Li-Ion Specific Energy (Wh/kg) Lead Acid Ni-Cd Ni-MH 5 5

Coupling of safety and energy Safety problems begin with flammability and electrochemical instability of electrolyte Worse with more energy Cost to industry >$1B in recent years Small 1 Wh computer batteries are not perfectly safe. Of 22 US airline Li battery fires, 11 happened in last 3 years. 6 Takeshita 2008 6

Safety of 5 kWh batteries Enough alkyl carbonate to annihilate a car. Li-ion batteries die quickly if operated at 60 oC and explode at 80 oC. Modified Prius http://blogs.edmunds.com/greencaradvisor/2008/06/ plug-in-toyota-prius-catches-fire-explodes.html

Replace liquid electrolyte by a solid Conventional Li Ion Li Polymer Cu Current Collector Porous Graphite Anode Composite Liquid Electrolyte Porous Cathode Composite Al Current Collector Solid Separator Polymer Cathode Composite Solid anode Flammable liquid electrolyte Solid state, no flammables Li Ion: <200 Wh/kg Li Polymer: ~250 Wh/kg Poor lifetime and capacity fade Stable polymer for best lifetime Activity began with California’s Zero Emission mandate in the 1990s 8 8

Dendrite growth during charging Conventional Li Ion Li Polymer Dendrite growth was a problem Cu Current Collector Porous Graphite Anode Composite Solid anode Liquid Electrolyte Solid Separator Porous Cathode Composite Polymer Cathode Composite Al Current Collector Al Current Collector Make polymer hard to prevent deformation Modulus=109 Pa, Monroe and Newman, 2005 9 9

Previous polymer electrolytes Ionic mobility is mediated by polymer chain motion. Fast polymer motion implies high conductivity and low modulus. Increasing modulus must decrease conductivity. Anion - polymer chain Li+ Polyethylene oxide showed promise. Unfortunately batteries failed due to lithium dendrite growth. Stiffness Limitation of prior polymer electrolytes 10 Conductivity 10

Solid polymer electrolyte - + Dendrites ~ mm + - LiTFSI salt r = [Li+]/[EO] Nanostructured conductor ~ 10 nm 11 11

Consequences of plug-in EV Basis: 100M EVs with 16 kWh batteries, 40 mi driving range CO2 emission reduced by 0.75 GT per year. 1.6 TWh of distributed energy storage. Potential solution to the renewable energy storage dilemma.

A Recent Success Story John Goodenough (U. Texas) proposes FePO4 as a cathode for Li batteries in 1997 but poor transport properties prevented implementation. Yet-Ming Chiang (MIT) shows that nanostructuring FePO4 solves the transport problem and establishes A123 in 2002. A123 goes public in September 2009. FePO4 is the likely cathode for first generation plug-in EVs.

Need for fundamental understanding The most misleading conclusion in (1)…” 180 kW is needed to charge a 15 kWh battery in 5 minutes” …. one must remember that the internal resistance of the battery will be of the order of R=1/4 ohm so that the power dissipated … is typically what you need to heat a four-story building! FePO4 15 kW battery can be charged in 5 min Kang and Cedar, Nature, 2009 Goodenough, et al. J. Power Sources, 2009 Cedar claims that slow ion transport in FePO4 is due to slow surface diffusion, based on simulations, but in the absence of direct experimental proof. This claim is strongly disputed by Goodenough et al. based on indirect arguments. Experimental measurements of bulk and interfacial transport would be useful.

Missing LBNL Battery Initiative Fundamental Studies on Battery Materials ($5M/year) Designing new electrodes (NERSC). Making model batteries with well-defined oxide nanoparticles (Foundry). Tracking atoms and orbitals through charge-discharge cycles (NCEM, ALS). Couple LBNL scientists who are not battery experts with battery experts. Fundamental study of the other charge carrier. This work is not consistent with the goals of the existing BATT program (supported by EERE). A new BES-supported program is needed for this work.

Future landscape Product We emit more than 1 molecule of CO2 for every 10-18 J of electricity we produce in a coal plant. Product Emission at 1 place. CO2 is concentrated. Easier to control, use, and legislate. Other alternative is to use clean energy (e.g. solar and wind). http://www.power4georgians.com/images/CoalFiredPowerPlantDiagram02.png

A possible option

Not an option Car with cement factory Interactions between Battery Center and Carbon Dioxide and Renewable Energy Centers is essential.

Summary Impact: 0.75 GT of CO2 emission, 1.6 TWh of storage. Major Obstacles: We may have arrived at the fundamental limit of today’s workhorse (Li-ion). Making next generation chemistries work is difficult to place on a Gandt chart. Lack of fundamental understanding of thermodynamics and transport impedes progress. Policies that reward lack an environmental footprint are essential as carbon-based energy will continue to be far more effective in terms of cost and energy density. Current battery work at LBNL is conducted within the BATT program. Connection between batteries, carbon capture, and renewable energy programs are natural. LBNL current expertise is more at the basic end of spectrum. LBL/ANL appear to have synergistic capabilities to basic-to-manufacturing spectrum. Industrial partners: Johnson Control, Dow Chemicals, A123 (BYD, Sanyo, LG Chem), IBM, Applied Materials. Viable funding plan: A new $25 M ANL/LBL Collaboration. A new $5 M program housed at MSD on fundamental studies on battery materials.