Energy Science and Technology III Lecture Winter Term 2015/16. Introduction to Batteries 7 January 2016

Transcription

1 Energy Science and Technology III Lecture Winter Term 2015/16 Introduction to Batteries 7 January 2016 Mario Wachtler Zentrum für Sonnenenergie- und Wasserstoff-Forschung (ZSW) Baden-Württemberg

2 Outline Basic Concepts Electrode and Cell Designs Battery Parameters Comparison of Battery Systems Battery Market -2-

3 Electrochemistry Please repeat the following concepts: ( EST III Lecture: Module Fuel cell fundamentals ) Oxidation and reduction reactions Nernst equation Formal potential Relation between Gibbs free enthalpy G and electrical potential difference E Faraday's law and Faraday's constant Ohm's law Overvoltage / overpotential Current-voltage curve Butler-Volmer equation -3-

4 Cell vs. Battery Cell Basic electrochemical unit Converts chemical to electrical energy (and vice versa for rechargeable cells) Consists of: electrodes, electrolyte, separators, current collectors, cell housings, terminals, etc. Battery Assembly of one or more cells connected in parallel or in series Consists of: cell(s), monitors, controls, fuses, diodes, case, terminals, etc. Source: SAFT Source: Daimler (1st generation Li-ion battery for S-class HEV) -4-

5 Non-Rechargeable vs. Rechargeable Batteries Non-rechargeable batteries Primary batteries Batteries Rechargeable batteries Secondary batteries Accumulators Storage batteries -5-

6 Shortcut Notation of Cell Chemistry negative electrode electrolyte positive electrode Negative electrode on the left Positive electrode on the right denotes a phase boundary denotes a liquid-liquid phase boundary (e.g. via salt bridge) During discharge electrons flow from left to right via external circuit and cations flow from left to right via electrolyte Cell voltage is positive: E = E(right) E(left) = E(+) E( ) > 0 Examples: Li electrolyte LiFePO 4 Li + FePO 4 LiFePO 4 E = 3.5 V Zn 0 Zn 2+ (aq.) Cu 2+ (aq) Cu 0 Zn 0 + Cu 2+ Zn 2+ + Cu 0 E = 1.1 V -6-

7 Primary and Secondary Batteries Selected Systems Primary batteries (Non-rechargeable batteries) Secondary Batteries (Rechargeable batteries, accumulators) Zn-carbon - Leclanché: Zn NH 4 Cl MnO 2 Zn-carbon - Zn chloride: Zn ZnCl 2 MnO 2 Alkaline MnO 2 : Zn KOH MnO 2 Magnesium: Mg Mg(ClO 4 ) 2 -Li 2 CrO 4 MnO 2 Zinc-silver oxide Zn KOH or NaOH Ag 2 O Mercury-zinc: Zn KOH or NaOH HgO Mercad: Cd KOH or NaOH HgO Zinc/air: Zn KOH O 2 Lithium: Li LiAlCl 4 -SOCl 2 SOCl 2 Li aprotic organic SO 2 Li aprotic organic MnO 2 Li aprotic organic FeS 2 Li aprotic organic (CF) n Li LiI I 2 poly-2-vinylpyridine anode electrolyte cathode Lead acid: Pb H 2 SO 4 PbO 2 Valve regulated lead acid (VRLA): Pb immobilised H 2 SO 4 PbO 2 Ni-Cd: Cd KOH Ni oxide Ni-MH: metal hydride KOH Ni oxide Li-Ion: LiC 6 aprotic organic Li (1-x) CoO 2 LiC 6 apro. org. Li (1-x) Ni 1/3 Co 1/3 Mn 1/3 O 2 LiC 6 aprotic organic FePO 4 Edison (NiFe): Fe KOH-LiOH Ni oxide Rechargeable alkaline manganese (RAM): Zn gelled KOH MnO 2 Sodium-sulfur: Na β''-alumina (~ NaAl 11 O 17 )ornasicons S Na-Nickel chloride (ZEBRA): Na β''-alumina + NiAlCl 4 NiCl 2 Zinc-bromine: Zn ZnBr 2 Br 2 Vanadium redox flow: V 2+ V x+, H 2 SO 4 V 5+ D. Linden, T.B. Reddy (eds.): Handbook of batteries, 3 rd ed., McGraw-Hill, New York (USA),

8 Basic Concepts Special Battery Types Dry Cells : No electrolyte leakage: Liquid electrolyte is contained in absorbent or separator Solid electrolyte Reserve batteries During storage a key component is separated from rest of battery. Battery is activated only before use. Excellent storage characteristics (chemical degradation and discharge are eliminated) Mechanically rechargeable batteries Mechanical replacement of discharged or depleted electrode Usually metal anode in metal/air batteries (e.g. Zn/air) Thermal batteries Battery is activated by heating, e.g. melting of solid electrolyte Especially for military applications (missiles, torpedos, weapon systems) -8-

9 Anode and Cathode Charge Discharge Electrolysis Galvanic element e + e + Li + Li + Cathode (is reduced) Anode (is oxidised) Electrochemical definition Anode (is oxidised) Cathode (is reduced) Anode Cathode Battery convention Anode Cathode -9-

10 Electrodes: Anode and Cathode Anode Negative electrode During discharge the anode gives electrons to external circuit and is oxidised. Red Ox + n e - Cathode Positive electrode During discharge the cathode accepts electrons from external circuit and is reduced. Ox + n e - Red Be aware: In electrochemistry the electrode which is oxidised (or at which oxidation takes place) is defined as anode and the electrode which is reduced (or at which reduction takes place) is defined as cathode. During discharge of a cell the negative electrode is oxidised and is thus the anode, and the positive electrode is reduced and is thus the cathode. During charge the oxidation / reduction reactions are reversed: hence, from a strict electrochemical point of view the negative electrode becomes the cathode and the positive electrode becomes the anode. To avoid confusion in battery science the terms anode and cathode are always used in the discharge sense, i.e. the negative electrode is called anode and the positive electrode is called cathode, irrespectively of whether the electrode is discharged or charged. To be on the safe side, negative electrode and positive electrode should be used. -10-

11 Basic Concepts Active vs. Inactive Materials Active materials Take part in the charge storage reaction: E.g. electrode materials, electrolyte in lead acid batteries etc. Inactive materials Do not take part in the charge storage reactions, but are needed to support the active materials E.g. conductive additives, binders, current collectors, electrolyte in Li-ion batteries, cell housing, etc. + Electrolyte solution Separator or polymer electrolyte Current collector (-) Current collector (+) [optional] Current collector coating (-+) Polymer binder (-+) Conductive additive (-+) Active material (-) Active material (+) [optional] Particle coating (-+) -11-

12 Basic Concepts Electrolyte Function / requirements: Conducting for ions Insulating for electrons (to prevent self-discharge) Can be with or without separator function: Separator function: prevent direct contact between anode and cathode (short circuit) Without separator function: liquid electrolytes, additional mechanical separator is required With separator function: solid electrolytes (including polymer electrolytes) -12-

13 Can act as active or inactive material: Basic Concepts Electrolyte Inactive material: electrolyte does not take part in net cell reactions, composition of electrolyte remains constant during charge and discharge E.g. Li-ion batteries: Anode: C 6 + Li + + e LiC 6 Cathode: LiFePO 4 FePO 4 + Li + + e Cell: C 6 + LiFePO 4 LiC 6 + FePO 4 Active material: electrode takes part in electrode reactions, composition of electrolyte changes during charge and discharge E.g. lead acid batteries: Anode: Pb + SO 2 4 PbSO 4 + 2e Cathode: PbO 2 + SO H + + 2e PbSO 4 + 2H 2 O Cell: Pb + PbO 2 + 2SO H + 2PbSO 4 + 2H 2 O (red: electrolyte components) -13-

14 Electrode Design Active material (e.g. MH) in a porous structure plus electrolyte Active material Additive (e.g. Co for NiOOH) Electrolyte The energy is stored inside the active materials (volume related) The energy conversion (power) takes place on the surface of the active materials (area related) Current collector (e.g. Ni foil (NiMH)) -14-

15 Electronic and Ionic Conductivity Electrode Active material e Li + For the charge / discharge reaction to occur electron and ion conduction is required: Electron conduction via current collector and active material Ion conduction via electrolyte and active material Active material: Insertion and conversion electrodes require diffusion of active species (ions) otherwise metal deposition occurs at surface Increase of electron conduction: Proper design of active materials, e.g. doping Conductive additives and carbon coating of active material: provide additional electron conduction pathways in electrode Increase of ion conduction: In active material: Nanoparticles: shorter diffusion lengths, grain broundary diffusion In electrode: increased porosity to provide more and better electrolyte access -15-

16 High Power vs. High Energy Optimized for power Optimized for energy High conductivity of electrolyte Avoid long diffusion paths (thin electrode layers, thin separators) Good grain to grain contact, electrically conducting agents Short distance from active material to current collector Fast reaction kinetics (electrode reaction) Very efficient electrode reaction and material usage Thick electrodes with high electrode mass Save inactive / passive components like additives or current collector -16-

17 Battery Components Electrodes and and current collector Safety valve / other safety features Electrolyte Housing mechanically stable gas/liquid-tight (H 2, electrolyte) chemically stable steel, Al, plastic or composite material Separator: Mechanical separation of electrodes Good ion conductivity Very thin -17-

18 Outline Basic Concepts Electrode and Cell Designs Battery Parameters Comparison of Battery Systems Battery Market -18-

19 Usually as negative electrode Dissolution during discharge Deposition during charge Ni-Cd, Li (metal), metal-air Cd Cd e Li Li + + e Electrode Types Metal Electrodes High capacity Problems with rechargeability, as metal deposition often occurs dendritic (safety problems) Lithium dendrite formation after repeated cycling F. Orsini, L. Dupont, B. Beaudoin, S. Grugeon, J.-M. Tarascon; Int. J. Inorg. Mater. 2 (2000),

20 Electrode Types Non-Reacting (Inert) Electrodes Are not reduced / oxidised during charge / discharge but deliver / accept electrons to reduce / oxidise active species dissolved in the electrolyte redox-flow battery, metal/air, fuel cells (C) + V 2+ (C) + V 3+ + e (C) + VO H + + e (C) + VO 2+ + H 2 O (C/catalyst) + O 2 + 2Li + + 2e (C/catalyst) + Li 2 O 2 electrical double-layer capacitor (C) + Cation + (C)... Cation + (C) + Anion + (C)... Anion May age and lose activity Vanadium redox flow battery Source: essib_innovative_elements/redox_flow _batteries.php (2013) -20-

21 Electrode Types Insertion and Conversion Electrodes During discharge / charge a species from the electrolyte is inserted into / deinserted from the electrode Li-ion, Ni-MH, lead acid LiC 6 C 6 + Li + + e FePO 4 + Li + + e FePO 4 MH + OH M + H 2 O + 2e NiOOH + H 2 O + 2e Ni(OH) 2 + OH redox supercapacitors RuO 2 + xh + + xe RuO 2-x (OH) x Good rechargeability Usually lower capacity than for metal electrodes -21-

22 Electrode Types Insertion and Conversion Electrodes Insertion Reactions Topotactic reactions without major changes of host material Good cycling stability Usually only small amounts of Li can be inserted into / extracted from the interstitial sites Low capacity Conversion Reactions New phases are formed during charge and discharge putting mechanical stress onto the system More difficult to obtain cycling stability Compounds can usually react with a larger amount of Li High capacity Source: M. Armand, J.-M. Tarascon; Nature 451 (2008),

23 Cell and Battery Designs Open batteries: Batteries with removable lid Batteries without case (e.g. power paper printable Zn MnO 2 thin-film battery) Vented batteries (geschlossene Batterien) Batteries with plug, gasses are emitted during charge (e.g. SLI lead acid) Valve-regulated batteries (verschlossene Batterien) Batterie with resealable valve and gas recombination cycle (e.g. VRLA) Sealed batteries Batteries with complete gas recombination cycle (Ni-Cd, Ni-MH) Batteries which do not show gassing (Li-ion) -23-

24 Cell Designs Bobbin Constructions Electrodes shaped in 2 concentrical cylinders Maximised amount of active materials Simple and cheap Small surface area for electrochemical reaction High internal resistance Low rate / power E.g. Zn-carbon primary cells Alkaline MnO 2 cells Source: Varta -24-

25 Cell Designs Wound Designs Spirally wound: cylindrical cells Elliptically wound: prismatic cells Electrodes and separators are wound up to form a jelly roll Thin electrodes, Large surface areas for electrochemical reaction Low internal resistance High rate / power More complex and expensive than bobbin construction Sony: Li-Ion battery rechargeable battery, catalogue, E.g. Li-ion batteries -25-

26 Cell Designs Cylindrical vs. Prismatic Cyclindrical Prismatic Sony: Li-Ion battery rechargeable battery, catalogue, Minimum diameter (>10 mm) Simple and cheap manufacturing (winding) Defined pressure on electrodes Defined path for gas release during opening of Problems with cooling especially for large cells (build-up of temperature gradients) Mechanically very robust Limited maximum capacity: approx. 40 Ah Bad shape factor, low packing density in module Thin cells possible (>3mm) More complex and costly manufacturing Easier cooling Defined pressure on electrodes Defined path for gas release during opening of Good shape factor, high packing density in modules -26-

27 Cell Designs More Prismatic Cell Designs Elliptically wound T. Knoche, Electrical Energy Storage Conference and Fair, Munich, E.g. Li-ion batteries -27-

28 Cell Designs Stacked Designs: Plate Design (last access: 01/2011) Thicker electrodes are possible (better ratio of active to inactive materials) Still large surface areas for electrochemical reaction Complex manufacturing and current collector design E.g. Lead-acid -28-

29 Cell Designs Bipolar Designs Bipolar electrodes: one side of the electrode acts as an anode in one cell and the other side acts as a cathode in the next cell Bipolar electrode must be ion-impermeable to avoid selfdischarge D. Linden; in D. Linden, T.B. Reddy (eds.): Handbook of Batteries, 3rd ed., McGraw Hill, New York, 2002; Ch. 3. Efficient design: reduced number of plates, elimination of external connections, reduced weight of the battery, increased energy density Shorter current pathway, lower internal resistance, higher power Uniform current distribution over entire surface of electrodes provides more efficient utilization of electrode materials High voltage batteries can be realised in small space Strong requirements for stability of bipolar electrodes and tightness of cell compartments Risk of higher self discharge due to shunt currents E.g. Lead-acid, redox flow batteries, Ni-MH Source: Altraverda -29-

30 Cell Standardisation Why standardisation: Ensure interchangeability of cells from different manufacturers Standardisation of: Size, shape, voltage and terminals Standards: International Standards: IEC (International Electrotechnical Commission) National Standards: E.g. ANSI (American National Standards Institute) Specific Nomenclatures from battery manufacturers F. Ciliberti, S. Wicelinski; in D. Linden, T.B. Reddy (eds.): Handbook of Batteries, 3 rd ed.; McGraw-Hill, New York, 2002; Chapter

31 Special nomenclature: Cell Standardisation by Size Cylindrical Cells AA ( double A ) AAA ( triple A ) C D etc. d = mm, h = mm d = mm, h = mm d = mm, h = mm d = mm, h = mm Systematic nomenclature: dd(d)hh(h) d = diameter in mm h = height in 1/10 mm h (Small) Li-ion cells: (d = ~18 mm, h = ~65.0 mm) (d = ~26 mm, h = ~65.0 mm) etc. Coin cells: 2032 (d = ~20 mm, h = 3.2 mm) etc. d Picture source: (2013) d h -31-

32 Special nomenclature: Cell Standardisation by Size Prismatic Cells Many l Systematic nomenclature: t ttwwll t = thickness in 1/10 mm w = width in mm l = length in mm w Picture source: (2013) (Small) Li-ion cells: e.g (t = ~5.5 mm, w = ~34 mm, l = ~50 mm) many more (customised sizes) Other systems for large cells (e.g. lead acid) -32-

33 Examples for Prismatic Cells Development of Prismatic Cells at Panasonic O. Sonnemann (Panasonic), Electrical Energy Storage Conference and Fair, Munich

34 Standardisation by Battery Chemistry F. Ciliberti, S. Wicelinski; in D. Linden, T.B. Reddy (eds.): Handbook of Batteries, 3rd ed.; McGraw-Hill, New York, 2002; Chapter

35 Standardisation by Shape F. Ciliberti, S. Wicelinski; in D. Linden, T.B. Reddy (eds.): Handbook of Batteries, 3rd ed.; McGraw-Hill, New York, 2002; Chapter

36 Outline Basic Concepts Electrode and Cell Designs Battery Parameters Comparison of Battery Systems Battery Market -36-

37 Typical Cell / Battery Parameters Nominal voltage Open circuit voltage Rated capacity Generally accepted typical operation voltage (e.g. Ni-MH and Ni-Cd: 1.2 V, Li-ion (graphite-lco/nca/nmc): V, Lead-acid: 2.0 V) Voltage under a no-load condition (is usually a close approximation of the theoretical voltage) Charge which is obtained at defined conditions Specific capacity / energy / power Charge / energy / power density Capacity / energy / power per mass of active material or cell (usually given in Ah/kg, Wh/kg, W/kg) Capacity / energy / power per volume of active materials or cell (usually given in Ah/L, Wh/L, W/L) Cycle life Calendar life Self-discharge Number of cycles until capacity falls below a threshold value (usually 80% of initial capacity) Time until capacity falls below a threshold value (usually 80% of initial capacity) Loss of charge per time starting from a fully charged state (usually given in %/month) -37-

38 General Requirements for Cells / Batteries Performance Battery life Safety Environmental impact Cost effectiveness High specific energy and energy density High specific power and power density Supported energy and power range High charge efficiency High energy efficiency Low self-discharge Low energy consumption of required auxilary units (heating, pumping, battery management, ) Long cycle life / high cycling stability Long calendar life High safety during regular operation High tolerance towards abuse Low damage potential Manufacture Operation Disposal / recycling Low acquisition costs Low operation costs Low maintenance costs -38-

39 Theoretical (Specific) Capacity of Electrode Materials Capacity Specific capacity Volumetric capacity Q spec,th = z F / M w Charge Capacity per mass, usually given in Ah/kg or mah/g Capacity per volume, usually given in Ah/L (derived from Faraday s law) Q spec,th = theoretical specific capacity, usually given in Ah/kg or mah/g z = number of transfered electrons F = Faraday constant, As/mol M w = molecular weight, usually given in g/mol Note: The specific capacity (as well as the volumetric capacity) are usually refered to the mass of discharged materials! E.g.: LIB cathode materials LiFePO 4 LiFePO 4 FePO 4 + Li + + e (discharged) (charged) z = 1 M w (LiFePO 4 ) = g/mol Q spec,th = Ah/kg -39-

40 Theoretical and Practical Specific Capacities of Electrode Materials Example 1: Theoretical capacity of graphite (C 6 ) Maximum intercalation state: 1 mol Li (1 mol e ) per mol C 6 : 1mole / molc 96485A s / mol 6 e 372mA h / g 72,1g / mol 3,6 A s / ma h C 6 Example 2: Practical capacity of LiCoO 2 At real conditions only 0.5 to 0.6 mol Li can be deinserted: 0,6mol e / mol 97,9g / mol LiCoO LiCoO A s / mol 3,6 A s / ma h e 164mA h / g 2 1C rate: 372 ma/g C/10 rate: 37.2 ma/g 10C rate: 3.72 A/g etc. 1C rate: 164 ma/g C/10 rate: 16.4 ma/g 10C rate: 1.64 A/g etc. -40-

41 Theoretical (Specific) Capacity of Cells Capacity refered to amount (mass) of anode and cathode active materials For a general reaction a A + b B c C + d D with z e transfered: (discharged) (charged) Q spec,th,cell = z F / (a M w,a + b M w,b ) E.g.: Li-ion cell: C 6 1M LiPF 6 / EC:DMC (1:1 by wt.) LiCoO 2 Anode reaction: 0.6 C Li e 0.6 LiC 6 Cathode reaction: LiCoO Li e + Li 0.4 CoO 2 Cell reaction: 0.6 C LiCoO LiC Li 0.4 CoO 2 a A b B z = 0.6 a = 0.6 b = 1 M w (C 6 ) = 72.1 g/mol M w (LiCoO 2 ) = 97.9 g/mol Q spec,th,cell = 94.6 mah/g Practical specific capacity will be lower, since inactive components increase the cell weight -41-

42 Electrode Balance and Cell Capacity For a cell to deliver a given capacity, both the anode and the cathode have to deliver this capacity. For safety reasons and / or to improve the ageing behaviour usually on electrode is limiting (smaller capacity) and the over one is over-dimensioned (higher capacity). (E.g. in Li-ion batteries with graphite anode, the anode is usually over-dimensioned). In this case the cell capacity corresponds to the capacity of the limiting electrode! E.g.: Given is a cell with an anode which delivers 1.2 Ah and a cathode which delivers 1.0 Ah. Limiting electrode = cathode Cell capacity = capacity of cathode = 1 Ah Practical specific capacity of cell = cell capacity per cell mass Theoretical specific capacity of cell = often calculated as cell capacity per sum of masses of active materials in anode and cathode (Note: other definitions are in use, check conventions before comparing values!) -42-

43 C-Rates (Cells and Batteries) Conventional definition for cells / batteries: A 1C rate corresponds to the current which allows a full charge or discharge of a cell in 1 h (for moderate rates*) I[A] = M C n [Ah] / 1[h] I Current C n Rated capacity (at a n h discharge* ) M multiple or fraction of C * Capacity decreases at high currents, therefore a capacity value determined at low currents should be used n is often omitted D. Linden, T.B. Reddy: Handbook of Batteries, 3rd ed., McGraw-Hill, New York, 2002, p E.g.: Battery with a rated capacity of 8 Ah (for a 5h discharge) C 5 = 8 Ah 1C-rate: M = 1 I = 8 A C/10-rate: M = 0.1 I = 0.8 A 10C-rate: M = 10 I = 80 A -43-

44 Conventions for electrode materials: (in analogy to cells and batteries) C-Rates (Electrode Materials) Based on practical capacity (of electrode or cell) E.g. LFP: practical capacity 160 mah/g 1C = 160 ma/g Based on theoretical capacity (of electrode or cell) E.g. LFP: practical capacity mah/g 1C = ma/g -44-

45 Influence of Current Rate on Capacity With increasing current the electrode / cell capacity decreases - since the materials / cell cannot be fully discharged - since the end-of-discharge (EOD) voltage is reached before the cell is fully discharged the discharge voltage decreases - due to increasing overvoltages and IR drop i.e. discharge energy decreases E.g.: LIB (Graphite/NCA), 7.5 Ah, GAIA EOD voltage Picture source: P. Kurzweil, K. Brandt, in J. Garche (ed.): Encyclopedia of Power Sources, Vol. 5, Elsevier, Amsterdam (The Netherlands), 2009, pp. 1ff. -45-

46 Cell Energy Specific energy energy per mass usually given in Wh/kg also often called energy density Energy density W = U(Q) dq = ~ U av Q W = (specific) energy U = cell voltage Q = (specific) capacity energy per volume usually given in Wh/L Practical specific energy refers to mass of complete cell Cell Voltage / V Theoretical specific energy is usually refered to sum of masses of active materials in anode and cathode ,0 0,2 0,4 0,6 0,8 1,0 1,2 1,4 1,6 1,8 Capacity / Ah U av -46-

47 Charge Efficiency and Energy Efficiency Charge efficiency Charge/discharge efficiency Coulombic efficiency QDCh Ah Q Ch Charge efficiency consideres charge losses (e.g. due to side reactions or due to selfdischarge) Typical values: Li-ion: ~100% (no side reactions) Lead acid: approx. ~90% Ni-Cd, Ni: approx. ~70% Energy efficiency WDCh Wh W Ch Energy efficiency considers charge losses (e.g. due to side reactions) and voltage losses (e.g. due to overvoltage) Typical values Li-ion: ~95% Lead acid: ~80% Ni-MH: ~75% Ni-Cd: ~65% Charge Factor CF Q Q Ch DCh 1 Ah Both charge efficiency and energy efficiency depend on the charging method used. -47-

48 Outline Basic Concepts Electrode and Cell Designs Battery Parameters Comparison of Battery Systems Battery Market -48-

49 Electrochemical Series Electrochemical Series (Standard reduction potentials) Theoretical Specific Energy System Ah/kg V Wh/kg Li//F Li//O Mg//O Zn//O H 2 //O (33,000 H 2 only) Li//S x Na//NiCl Li//MO ca C 6 //Li 1-x CoO 2 with x max =0,6 114 rated: 3.7 max. 4.2 ca

50 Nominal Voltage and Theoretical Energy Density System Nominal voltage / V Theor. energy density * / Wh/kg Cell reaction (left: charged state / right: discharged state) (blue: anode / red: cathode) Pb/PbO Ni/Cd Pb + PbO H SO PbSO H 2 O Cd + 2 NiOOH + 2 H 2 O 2 Ni(OH) 2 + Cd(OH) 2 Ni/MH /6 MmNi 5 H 6 + NiOOH Ni(OH) 2 + 1/6 MmNi 5 ** Ni/Fe Fe + 2 NiOOH + 2 H 2 O 2 Ni(OH) 2 + Fe(OH) 2 Ni/Zn Zn + 2 NiOOH + 2 H 2 O 2 Ni(OH) 2 + Zn(OH) 2 Zn-Air Zn + O 2 2 ZnO Na/NiCl Na + NiCl 2 2 NaCl + Ni Li/MnO ~ 1000 x Li + MnO 2 Li x MnO 2 (theor. x max = 1) Li-Ion C 6 /LiMO ~ 420 x LiC 6 + Li 1 x CoO 2 x C 6 + LiCoO 2 (x max = ~0.6) * Energy density referred to sum of masses of anode and cathode active materials ** Mm = misch metal (= mixture of rare earth metals) -50-

51 Theoretical vs. Practical Energy Density Na/NiCl 2 Li/MnO 2 O 2 /Zn Wh/kg Pb/PbO 2 Ni/Cd Ni/MH Ni/Fe Ni/Zn C/LiMO 2 Pb/PbO 2 Ni/Cd Ni/MH Ni/Fe Ni/Zn C/LiMO 2 Na/NiCl 2 Li/MnO 2 O 2 /Zn 0 theor. Theoretical spez. Energie specific energy prakt. Practical Spez. specific Energie energy Pb/PbO2 Ni/MH Ni/Zn Na/NiCl2 O2/Zn Ni/Cd Ni/Fe C/LiMO2 Li/MnO2-51-

52 Voltage Ranges 4,5 4,0 Li-Ion 3,5 Cell voltage / V 3,0 2,5 2,0 Na/NiCl 2 Lead acid DLC (org.) 1,5 1,0 0,5 0,0 NiMH DLC (aqu.) % 120 Stability window of H 2 O DLC = electrical double layer capacitor (= supercapacitor) -52- (discharged) 100 C/C n (charged)

53 Energy and Power Ragone* Diagramme +HDLC Redox-flow * David. V. Ragone -53-

54 Energy Efficiency Efficiency efficiency in % Lead acid Li-Ion DLC HDLC Redox Flow NiMH Metal Air Fuel Cell -54-

55 Costs Costs/kWh Costs in /kwh Costs/kWh 1 Lead acid Li-Ion DLC HDLC Redox Flow NiMH Metal Air Fuel Cell Li-ion: Small consumer cells: <300 /kwh Large cells: /kwh, costs rapidly decreasing -55-

56 Cycle Life Cycle Lifetime (100% DOD Lead acid Li-Ion DLC HDLC Redox Flow NiMH Metal Air Fuel Cell -56-

57 Safety Safety Level (1-10) Lead acid Li-Ion DLC HDLC Redox Flow NiMH Metal Air Fuel Cell For Li-ion, redox flow and metal air safety depends strongly on specific technology -57-

58 Comparison of Technologies Costs (1=100 /kg) specific Energy (1=200 Wh/kg) 1 0,9 0,8 0,7 0,6 0,5 0,4 0,3 0,2 0,1 0 LAB NiMH Me-Air DLC Li-Ion specific Power (1=5000W/kg) Energy Efficiency in % Lifetime (cycles) (1=3500 Cycles) Low temp. Performance (1 = -40 C) -58-

59 Outline Basic Concepts Electrode and Cell Designs Battery Parameters Comparison of Battery Systems Battery Market -59-

60 Battery Market Volume Global revenues: 2009: 47.5 billion USD 2015: 74 billion USD Revenue contributions of different battery chemistries (2009) Source: Frost and Sullivan 2009: Primary batteries: 23.6% of global battery market, share is decreasing Secondary batteries: 76.4% of global battery market, share is increasing -60-

61 Battery Market Development Rechargeable Batteries (without Lead-Acid) Cost base! H. Takeshita, H. Mukainakano, Institute of Information Technology; 28th Int. Battery Seminar & Echibit, Orlando (FL, USA),

62 Recommended Literature D. Linden, T.B. Reddy (eds.): Handbook of batteries, 3 rd ed., McGraw-Hill, New York (USA), J. Garche (ed.-in-chief): Encyclopedia of electrochemical power sources, Vols. 1 5, Elsevier, Amsterdam (The Netherlands), A. Jossen, W. Weydanz: Moderne Akkumulatoren richtig einsetzen; Leipheim and Munich (Germany), (Book in German language). J.O. Besenhard (ed.): Handbook of battery materials; Wiley-VCh, Weinheim (Germany),

63 Acknowledgements Parts of this lecture are based on lectures by Prof. Andreas Jossen (TU Munich, formerly ZSW) and Prof. Werner Tillmetz (ZSW and University of Ulm) -63-

64 Thank you for your attention! Zentrum für Sonnenenergie- und Wasserstoff-Forschung Baden-Württemberg Helmholtzstraße 8, Ulm Stuttgart Photovoltaics & Solab -64- Energy Policy & Energy Carriers Widderstall Solar test-field Ulm Electrochemical Energy Technologies Ulm elab (Battery research centre) FPL (Battery production research)