LITHIUM/AIR SEMI-FUEL CELLS: HIGH ENERGY DENSITY BATTERIES BASED ON LITHIUM METAL ELECTRODES

LITHIUM/AIR SEMI-FUEL CELLS: HIGH ENERGY DENSITY BATTERIES BASED ON LITHIUM METAL ELECTRODES Steven J. Visco, Eugene Nimon, Bruce Katz, May-Ying Chu, and Lutgard De Jonghe PolyPlus Battery Company 2431 5th Street, Berkeley, CA 94710 SVisco@polyplus.com Scalable Energy Storage: Beyond Li-Ion, Almaden Institute, August 26, 27, 2009

Technologies Under Development Lithium/Sulfur - rechargeable (licensed product) Lithium/Air - (primary & secondary) Lithium/Seawater - primary

Li/Aqueous Batteries? Lithium Electrode Lithium reacts with water: Li + H2O = LiOH + 1/2 H2 Water-stable, Li + conductive solid electrolyte Unstable to reduction by Li Li + electrolyte stable to both lithium metal & solid electrolyte

SOLID ELECTROLYTES RbAg4I5 σ=0.27 S/cm Na-β -alumina σ=0.2 S/cm (350 o C) LiI Li2S P2S5 σ=10-3 S/cm 50 microns LiPON (Li3PO4Nx) σ=10-6 S/cm Lisicon - LiM2(PO4)3 σ=10-4 to 10-3 S/cm

Solid-State PLE Cu3N/Li3N Solid-state protected anode - Cycling of solid-state protected anode in 1M LiOH at varying current densities: 1) 1 ma/cm 2 ; 2) 5 ma/cm 2 ; 3) 10 ma/cm 2 ; 4) 15 ma/cm 2 ; 5) 1 ma/cm 2

1ST PUBLIC PRESENTATION OF THE PROTECTED LITHIUM ELECTRODE (PLE) 12th International Meeting on Lithium Batteries, Nara, Japan, June 27th July 2nd, 2004 Lithium Metal Aqueous Batteries, Abstract No. 53, Lithium Fuel Cells, Abstract No. 396 Lithium Air Batteries, Abstract No. 397 (S.J. Visco, E. Nimon, B. Katz, L.C. De Jonghe, and M.Y. Chu) U.S. Patent 7,282,295; Protected active metal electrode and battery cell structures with non-aqueous interlayer architecture ; S.J. Visco; Y.S. Nimon;, B D. Katz; and L.C. De Jonghe filed April 14, 2004 U.S. Patent 7,491,458; Active metal fuel cells, S.J. Visco; Y.S. Nimon, B D. Katz; and L.C. De Jonghe; filed April 14, 2004

Lithium/Water Chemistry (Low equivalent weight of lithium combined with the high voltage for the Li/Seawater couple leads to unprecedented energy density for practical Li/Seawater Cells) Li/O2 in aqueous electrolytes: Basic electrolyte: 4Li + O2 + 2H2O = 4LiOH Acidic electrolyte: 4Li + O2 + 4H+ = 2H2O + 4Li Li/O2 in non-aqueous electrolytes: Li + O2 = Li2O2 (peroxide) Li/Water: Basic electrolyte: 2Li + 2H2O = 2LiOH + H2 Seawater (ph=8.2): 2Li + 2H2O = 2LiOH + H2 E = 3.45 V E = 4.27 V E = 2.96 V E = 2.22 V E ~ 2.60 V The gravimetric capacity of lithium is 3800 mah/g; Li/Seawater batteries make use of both the dissolved oxygen (E=3.45 V) and water reduction (E=2.6 V) leading to a nominal voltage of about 2.8 volts for Li/Seawater battery under discharge. According, the theoretical specific energy is 3800 ma/g x 2.8 V ~ 10,000 Wh/kg.

Stability Window for H 2 O (Conventional vs. Solid Electrolyte Protected Li) Conventional Technology Protected Anode W. Li, W. R. McKinnon, and J. R. Dahn, J. Electrochem. Soc. 141, 2310 (1994) Expanded potential window enables development of stable Li/Air & Li/Water cells

Li/Air Aqueous Solid state/aqueous Interface Solid-state, non-aqueous, ionic liquid, polymer electrolyte

Stability of Solid Electrolyte in Aqueous Media

Discharge of Protected Lithium Metal Electrodes More than 5 mm lithium discharged in in each test at 100% utilization 0.5 ma/cm 2 2.0 ma/cm 2 1.0 ma/cm 2 Figure. 5. Discharge of thick protected anodes (Li foil is 5.3-5.6 mm) in aqueous neutral electrolyte used in Li/Air batteries. Discharge current density: 1) 2.0 ma/cm 2 ; 2)1.0 ma/cm 2 ; 3) 0.5 ma/cm 2. End of cell discharge corresponds to Li depletion. Data provided by PolyPlus Battery Company.

Protected Li electrode Li/Air Technology Compliant seal Flexible seal allows volume change and maintains hermetic enclosure (Tested to 10,000 psi) LiM2(PO4)3 Solid electrolyte

Commercial air electrode & Aqueous LiOH electrolyte PolyPlus air electrodes & PolyPlus catholytes Gen I Gen II Gen III Gen IV Gen V Gen VI

Discharge of Aqueous Li/Air using PLE Li/Air Cell (800 Wh/kg) Discharge of lithium/air cells having double-sided PLEs with compliant seals in aqueous catholyte at varying current density: 1) 1.0 ma/cm 2 ; 2) 0.5 ma/cm 2 ; and 3) 0.2 ma/cm 2

Non-Aqueous Li/Air Corrosion of Li electrode by water is unavoidable with this approach Corrosion of Li electrode is eliminated with this approach insoluble Li2O2 insoluble Li2O2 Choice of catholytes is limited PolyPlus issued US Patent Choice of catholytes nearly unlimited

Cycling of Li/Air Cell with Protected Li Anode and Non-Aqueous Catholyte Li electrode thickness: 40 µm Discharge/Charge: 0.1 ma/cm 2 for 10 hrs (~5 µm of Li) Cell Voltage, V 5 th cycle 22 nd cycle Time, hrs Cycling performance of Li/air cell with nonaqueous catholyte comprising LiTFSI in DMF EG.

Rechargeable Li/Air using PLE and non-aqueous catholyte 2 mah/cm 2 /cycle Cycling Cycling performance performance of Li/air of Li/Air cell cell with with nonaqueous non-aqueous catholyte electrolyte. comprising Charge/discharge: LiTFSI in DMF EG. 0.4 ma/cm 2 Charge/discharge: for 5 hrs; thickness 0.4 macm of Li plated 2 for 5 and h; thickness stripped during of Li plated cycling and is stripped ~10 μm during cycling: 10 microns

Rechargeable Li/Air To do list: Develop thin or wind-able solid electrolyte membranes to increase cell surface area Develop electrocatalysts for the non-aqueous oxygen electrode Explore non-aqueous electrolytes and complexing agents to increase solubility of Li2O2 Develop suitable electrode microstructures for deep reversible cycling of oxygen electrode Demonstrate suitable cycling of lithium electrode for traction applications

ADVANTAGES OF LITHIUM/AIR Li/Air Cell (800 Wh/kg) Extremely high specific energy (rivaling that possible for hydrocarbon fuel cells); commercial cells should reach 1000 Wh/kg Energy for reaction is not contained in cell; large battery packs may have a safety advantage for that reason Environmentally benign system

Providing Power for Marine Devices The majority of the oxygen in the earth s atmosphere is produced from photosynthetic processes occurring in the ocean. This is approximately sixty to seventy percent in total. Slide courtesy of Dr. James Bellingham Monterey Bay Aquarium Research Institute (MBARI)

The Protected Anode Fully functional protected lithium electrode; lithium electrode is stable to a broad range of protic and aprotic solvents including water; 2400 Wh/kg with a 2.8 V cathode.

Discharge of Protected Li Electrode In Seawater at Variety of Rates Li Thickness: 5.1-5.4 mm End of discharge corresponds to Li depletion Rigid Seal Anode potential vs. SHE, V 1.0 ma/cm 2 0.8 ma/cm 2 0.2 ma/cm 2 0.1 ma/cm 2 ~ 15 months of discharge Time, days

Instrumented 60-liter Tank for Testing Li/Seawater Batteries

Discharge of Li/Seawater (O 2 ) Cells Having Double-Sided Protected Lithium Anodes in 65-L Tank Glass-ceramic plates 150 µm in thickness 3.0 V Cell voltage, V 2.8 V End of discharge corresponds to lithium depletion 1.0 ma/cm 2 0.5 ma/cm 2 Time, hrs Discharge at 0.5 ma/cm 2 : 2268 mah (1.14 mm Li) Discharge at 1.0 ma/cm 2 : 2247 mah (1.13 mm Li)

Discharge of Double-Sided Ceramic-Protected Lithium Anodes Having Flexible Seal in Seawater Sintered ceramic plates 260-270 µm in thickness Lithium thickness: 1.1-1.3 mm (2.2-2.6 mm total) Anode potential vs. SHE, V For all cells end of discharge corresponds to lithium depletion 1.0 0.5 0.2 0.15 ma/cm 2 ma/cm 2 ma/cm 2 ma/cm 2 105 days of discharge 0.1 ma/cm 2 Time, hrs

Li/Seawater Batteries are Environmentally Benign

Testing Under Realistic Ocean Conditions Will Biofouling Occur on Protected Anode? PolyPlus, MBARI, Scripps Protected Li anode Li = Li + + e - Pacific Ocean 10 meters Li + Li + Li + Lithium Li + Li + Toxic Non-Toxic

Deep Water Batteries Best marine batteries deliver 50 to 250 Wh/kg Li/Seawater should exceed 1000-1500 Wh/kg

MARKETS Lithium/Air & Lithium/Seawater Technologies

MANUFACTURING

The Protected Anode Fully functional protected lithium electrode; lithium electrode is stable to a broad range of protic and aprotic solvents including water; 2400 Wh/kg with a 2.8 V cathode.

OHARA Glass-Ceramic and Tape-Cast Membranes Glass-ceramic membranes: Ohara Japan Tape-cast membranes: OHARA U.S.

MANUFACTURING PolyPlus is working with Quallion LLC, a potential manufacturer of Li/ Air and Li/Seawater batteries. Quallion is now developing pack designs for commercial Li/Air products.

NEW OPPORTUNITIES Deep ocean New Battery Chemistry Drug Delivery

IMPLANTABLE POWER SUPPLIES Should last 2 times longer than Li/I2

IMPLANTABLE POWER SUPPLIES Should last 2 times longer than Li/I2

Novel Drug Delivery Systems Bipolar Disorder

Ionotophoretic Li+ Drug Delivery Electrochemical drug delivery (iontophoresis) ultra-compact Li source e - Li blood conc. Protected Li Electrode oral lithium _ Li + Biological medium Time + Ag/AgCl Electrode Li + AgCl = LiCl + Ag toxic Live pig skin therapeutic

Intellectual Property (IP) Assets Li - SOCl2 New Biomedical E N Li - Sulfur E R Li-Patch G Y Li-Air Secondary B a Li -Air Primary Other T E t t e C H r i N O e Li-Seawater PolyPlus Anode Protection Lithium (metal) PolyPlus Anode Protection Electrolyzers Li C x (carbon) PolyPlus Protected Anode Technology PolyPlus Anode Protection Lithium (metal) Li Cx (carbon) Fuel Cells Li M x (alloys) Metal s L O Li-Polymer Film Thin G Y Solid State Innovate & Protect IP 72 Issued Patents & 60 Pat. Apps. Domestic and foreign patent coverage Internal IP Circle leads to new innovations Solidify Core IP Employee Retention = IP Retention Internal IP Circle strengthens core protection Monetize IP Assets Intellectual Property Assets Leverage IP (JV, Gov t funding, strategic alliances) License secondary IP (field of use) Sell prepackaged secondary IP portfolios New IP = New Business

Relevant PolyPlus U.S. Patent Applications U.S. Patent Application No. U.S. Patent Application Title 20070172739 COMPOSITE SOLID ELECTROLYTE FOR PROTECTION OF ACTIVE METAL ANODES 20070117007 LI/AIR NON-AQUEOUS BATTERIES 20070051620 Polymer adhesive seals for protected anode architectures 20070037058 Compliant seal structures for protected active metal anodes 20060078790 Solid electrolytes based on lithium hafnium phosphate for active metal anode protection 20050175894 Protected active metal electrode and battery cell structures with non-aqueous interlayer architecture 20050100793 Active metal electrolyzer 20050100792 Active metal fuel cells 20040197641 Active metal/aqueous electrochemical cells and systems 20040191617 Ionically conductive membranes for protection of active metal anodes and battery cells 20040142244 Ionically conductive composites for protection of active metal anodes 20040131944 Compositions and methods for protection of active metal anodes and polymer electrolytes 20040126653 Ionically conductive composites for protection of active metal anodes 20030088971 Encapsulated alloy electrodes 20020182508 Coated lithium electrodes 20010041294 Plating metal negative electrodes under protective coatings

Fish love lithium