Brief I ntroduction to Rechargeable Lithium Ion Batteries

1. Yu GROUP Seminar Series Brief Introduction to Rechargeable Lithium Ion Batteries Lyu Chao 2019/01/26

2. Contents 1 2 3 Component Principle Introduction 4 Summary

3. Introduction 1 They all need batteries, especially lithium-ion batteries.

4. Introduction 1 What’s battery? A Battery is a device that converts chemical energy into electrical energy in a cup, tank, or other container or part of a composite container containing an electrolyte solution and metal electrodesto generate an electric current. Chemical battery Primary battery Rechargeable battery Lithium-ion battery zinc-manganese battery silver-zinc battery mercury battery Lead-acid battery nickel-cadmium battery

5. Introduction 1 Lithium (Li) 1. Lithium is the lightest metallic element on earth and is known as the most negative standard electrode potential (-3.045V); 2. Batteries with lithium metal as the negative electrode have high energy density and operating voltage, and the theoretical capacity of lithium metal is as high as 3860Ahkg-1. 4 Li + O₂ = 2 Li₂O 2 Li + 2 H₂O = 2 LiOH + H₂↑

6. Introduction 1 The development of Lithium-ion battery In 1970s, Exxon company used TiS2 as the anode material and lithium metal as the negative electrode material to make the first lithium battery. In 1980, J. B. Goodenough invented LiCoO2 . In 1981, Sanyo company lithium-carbon anode . In 1991, Sony unveiled the first commercial lithium-ion battery .

7. Introduction 1 Comparison of the different battery technologies in terms of energy density. Nature. 2001 Nov 15;414(6861):359-67

8. Introduction 1 Energy Environ. Sci., 2012, 5, 7854–7863

9. Introduction 1 Lithium ion battery features

10. Principle 2 The main components of lithium-ion batteries Positive electrode (cathode) Negative electrode (anode) Shell Septum Electrolyte

11. Principle 2 Common lithium-ion battery configurations Nature. 2001 Nov 15;414(6861):359-67

12. Principle 2 Cathode: LiCoO2Li1-xCoO2 +xLi++xe- Anode: 6C +xLi+ +xe-LixC6 Total: LiCoO2Li1-xCoO2 +LixC6 Energy Environ. Sci., 2012, 5, 7854–7863

13. Principle 2 μA< ELUMO ; μC > EHOMO Chem. Mater., Vol. 22, No. 3, 2010

14. Principle 2 Li+ has a high diffusion coefficient in the electrode. — quick charge and discharge Selection requirements The metal ion has a high REDOX potential in the embedded compound.— the output voltage A cathode material can reversibly insert and release large quantities of lithium ions - high volume The REDOX potential changes a little— voltage is stable The main structure is basically unchanged– cyclic performance Good chemical stability Both high electronic conductivity and ion conductivity- reduce polarization and large current Low price and environmental protection

15. Component 3 Classification of positive electrode materials Transition metal with variable valence state ---- redox reaction; Lithium ion migration channels ---- space structure NPG Asia Materials volume 8, page e254 (2016)

16. Component 3 Layered structure ― LiCoO2 Crystal structure: α-NaFeO2 type layered structure; Hexagonal system, R3m space group Good ionic conductivity: diffusion coefficient10-7~10-9 cm2/s; Good electronic conductivity σe: 10-3 S/cm Nat Mater. 2003 Jul;2(7):464-7

17. Component 3 The synthetic method of LiCoO2 —— Solid phase reaction Air +CO2 PVA Co3O4 （1~3μm） Granular mixture （1~3mm） Li/ Co> 1 Calcination 700~900℃ 12~24h LiCoO2 （15~20μm） Li2CO3 （1~3μm） 4Co3O4 + 6Li2CO3 + O2↑→12LiCoO2+ 6CO2↑ Advantages: simple process, easy operation, suitable for industrial production; Disadvantages: difficult to mix materials evenly, high energy consumption, large and irregular particles in shape; From Sony company

18. Component 3 Other synthesis methods Template method Coprecipitation method Sol-gel method Hydrothermal method Advantages: sufficient contact between Li+ and Co2+, approximately atomic-level mixing, easy control of particle size and phase composition; Disadvantages: The procedure is tedious；the cost is high, it is not easy the industrialization production;

19. Component 3 Electrochemical properties of LiCoO2 Theoretical specific capacity: 274mAh/g; Actual specific capacity: 130~140mAh/g; Ionics (2014) 20:1525–1534

20. Component 3 Spinel structure― LiMn2O4 Crystal structure: Tetragonal system； the space group is Fdm； Good ionic conductivity: diffusion coefficient 10-14~10-12 cm2/s; Theoretical specific capacity: 184 mAh/g; Actual specific capacity: ~120 mAh/g; Progress inNaturalScience:MaterialsInternational2013;23(3):256–272

21. Component 3 Severe capacity decay occurs during the cycle （LiMn2O4） 1. The dissolution of Mn2+: 2Mn3+(s) → Mn4+(s) + Mn2+(l) High oxidizing; Have reaction with electrolyte Dissolved in the electrolyte Journal of The Electrochemical Society, 1997, 144(8): 2593-2600

22. Component 3 Severe capacity decay occurs during the cycle （LiMn2O4） 2. Jahn-Teller effect: At the end of discharge, the Jahn-teller effect occurs on the surface of several particles first, then diffuses over the entire component Cubic structure Tetragonal structure Journal of The Electrochemical Society, 2004, 151(2): A204-A208

23. Component 3 Olivine structure― LiFePO4 Crystal structure: Pbnm orthogonal space group； Theoretical specific capacity: 170 mAh/g; Progress in Natural Science 23(3):256–27

24. Component 3 Olivine structure― LiFePO4 FePO4 has the similar structure with LiFePO4 ,and the volume is also close —— Good cycle performance; Charge：LiFePO4－xLi+－xe-→ xFePO4 +(1-x) LiFePO4 Discharge：FePO4+xLi+ + xe- → xLiFePO4 + (1－x)FePO4 Energy Environ. Sci., 2012,5, 5163-5185

25. Component 3 Comparison of common positive elevtrodematerials and their properties

26. Component • Lithium metal anode • Carbon based anode • Silicon based anode • Germanium based anode • Tin based anode • Li4Ti5O12 anode 3 Classification of negative electrode materials

27. Component 3 Three typical reaction mechanisms Chem. Soc. Rev., 2015,44, 5926-5940

28. Component 3 Carbon based anode Crystal structure: AB stacking； Stage： The number of graphite layers spaced between two adjacent embedded atomic layers. Three stages

29. Component 3 Carbon based anode —— graphite 6C +xLi+ +xe-LixC6 Theoretical specific capacity: 372 mAh/g; Energy Environ. Sci., 2011, 4, 3243

30. Component 3 Carbon based anode —— Carbon nanostructured materials

31. Component 3 Li4Ti5O12 Crystal structure: Spinel structure ； the space group is Fd3m； Theoretical specific capacity: 175 mAh/g; Redox potential: 1.55V（vs. Li+/ Li); Zero strain. Li4Ti5O12 Li7Ti5O12 New J. Chem., 2015,39, 38

32. Component 3 Electrochemical properties of Li4Ti5O12 Journal of Power Sources 195 (2010) 6250–6254

33. Component 3 Comparison of common negative elevtrodematerials and their properties

34. Component 3 Electrolyte Non-aqueous organic liquid electrolyte Polymer electrolyte (all solid, colloid) Inorganic solid electrolyte Chem. Mater., Vol. 22, No. 3, 2010

35. Summary Thank you! 4 • The concept of rechargeable battery and the main classification; • The development of Lithium battery and the working principle; • Positive and negative electrode materials and electrolyte;