Lithium Ion Batteries - for vehicles and other applications Tekes 2008-12-03 Kai Vuorilehto / European Batteries
What do we need? High energy (Wh/kg) driving a car for 5 hours High power (W/kg) accelerating Toyota Prius for 5 seconds These are hard to achieve simultaneously so we need basic knowledge about batteries
Basic division Primary batteries (non-rechargeable) hardly practical for vehicles etc. in Finnish paristo Secondary batteries (rechargeable) in Finnish akku What is the scientific difference?
Cell constructions Button cells (small) Cylindrical cells (medium size) Bobbin or Swiss roll Prismatic cells (large) Stacked Elliptical Special geometries (eg. for satellites)
Button cell
Cylindrical cell - bobbin
Cylindrical cell swiss roll
Prismatic cells
Special design Nickel-hydrogen battery for Iridium satellites
Secondary batteries - chemistries Pb-PbO 2 NiOOH-Cd NiOOH-MH Li-ion C-CoO 2 C-Mn 2 O 4 C-FePO 4 Ti 5 O 12 -Mn 2 O 4
Secondary batteries - energy Pb-PbO 2 35 Wh/kg NiOOH-Cd 35 Wh/kg NiOOH-MH 75 Wh/kg Li-ion (C-CoO 2 ) 130-190 Wh/kg Li-ion (C-Mn 2 O 4 ) 110-150 Wh/kg Li-ion (C-FePO 4 ) 90-140 Wh/kg
Principle of the lithium-ion battery
Principle of the lithium-ion battery NOT a lithium battery, as there is no metallic lithium Metallic lithium could form dendrites and cause short circuit Lithium ions are intercalated in host lattices (graphite etc.) Each ion has its "own home"
Negative electrodes (anodes) Graphite standard material high voltage, 3.6V with CoO 2 Titanate extremely stable fast charge and discharge low voltage, about 2V with CoO 2» (promising for hybrid use?)
Positive electrodes (cathodes) Cobalt oxide standard material, 3.6V expensive, toxic and dangerous Manganese oxide cheap, slightly soluble, 3.7V Iron phosphate extremely stable, fast charge and discharge lower voltage 3.2V
Electrolytes Ethylene carbonate & its derivatives as solvent Lithium hexafluorophosphate as salt Hardly any alternatives Lithium polymer batteries can use polymer electrolytes
Structure It must be easy to fabricate It must be robust It must keep stack pressure It must let heat to come out» (important for hybrid use!) Small volume is advantageus
Cylindrical
Elliptical
Stacked
Players on the field Company Products, chemistries A123 medium iron phosphate, large format in R&D, USA & China Kookam large cobalt oxide cells in R&D, Korea Valence medium iron phosphate cylindrical cells, USA & China Saft large and medium, cobalt oxide, & iron phosphate, France Samsung large iron phosphate (Power), in R&D, Korea LG large and medium manganese oxide in R&D, Korea International Battery large iron phosphate, USA K2 medium iron phosphate, USA & China European Batteries/K2 large iron phosphate, together with K2, Finland Small cell producers: Sanyo, Sony, Panasonic,
Connecting cells Parallel internal resistance should be similar not a big problem Series capacity should be very similar overcharge & overdischarge is problematic Parallel & Series first parallel, then series
Battery management system controlling voltage in cell level avoid overcharge & overdischarge controlling temperature in cell level stop the system in time calculating state of charge compensating differences in state of charge
Safety Chemistry Production technology Battery management system Fuses, pressure valves etc.
Citius, altius, fortius Safer Cheaper Smaller
A Finnish company, founded 2008, owned by its investors, FEVT and key personnel Company develops, manufactures and sells advanced large-scale (>40 Ah) rechargeable lithium-ion batteries and battery systems Office in Espoo and R&D site in Varkaus The company is starting to produce large-scale lithium-ion batteries in Varkaus Factory design started January 2008 Construction work started September 2008 Manufacturing facility in full production Autumn 2009 Facility: 10 000 m 2 Capacity: 10 000 000 Ah/month 32 MWh/month
Company has 4.5 million euro share capital or commitments for shares The ownership structure will develop, when new investors come in The company s American partner K2 has an option to become a shareholder with 10% ownership. The option is valid through year 2009. Note: Eboy owns approx 11% of common shares of K2
LFP Our technology Choice In our R&D process For anode material Source: Monitor Consulting, 2008
400 Energy Density vs Specific Energy * Energy Density, Whr/l 350 300 250 200 150 100 50 Pb Acid NiCd Li-Polymer LiFePO4 NiMH Li Ion: LiCoO2 0 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 Source: Company and K2 Specific Energy, Wh/kg
Lead Acid NiCd NiMH Li ion LiCoO2 Li ion LiFePO4 Battery/pack specific energy, Wh/kg 30-50 45-80 60-110 110-200 100-160 Cycles 200-300 1500 300-500 500-1000 2000+ Charge time, hr 2-5 1 2-3 1-3 1 2 Self discharge/mo, % 5 20 30 3 2 Avg operating Voltage 2 1.2 1.2 3.6 3.2 Relative battery/pack cost 1X 3-4X 3-4X 4-5X 3-4X Relative safety 2 1 1 4 2 Relative environmental 3 4 2 2 1 Source: K2
Battery design capabilities; the jointly developed large-format prismatic lithium-ion battery design is costefficient, environmentally friendly and light weight with high energy contents. Material science: the advanced formulation and coating techniques obtained from K2. Efficient production technology: low raw material consumption and fast production Vertical integration from cell chemistry to system design: the close co-operation with FEVT we can address design requirements at the chemistry, battery or battery system levels
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