A school chemistry project about batteries

1. Presantation on working of batteries Submitted by: ArditMeti & ErdoanMuca

2. What is BATTERY? A system which converts chemical energy into electrical energy. More correctly, a battery is an electrochemical cell: Galvanic Cells Electrolytic Cells

3. HISTORY OF BATTERIES 1800 Voltaic pile: silver zinc 1836 Daniellcell 1899 Junger: nickel cadmium cell 1946 Neumann: sealed NiCd 1960s Alkaline, rechargeable NiCd 1970s Lithium, sealed lead acid 1990 Nickel metal hydride (NiMH) 1991 Lithium ion 1992 Rechargeable alkaline 1999 Lithium ion polymer

6. ANODE

7. CATHODE

9. WORKING OF BATTERIES Nickel-Cadmium Battery Cathode NiO(OH) Anode Cd Separator NaOH

10. WORKING OF BATTERIES Nickel-Cadmium battery:- the reactions look something like this: Oxidation:- Cd(s) + 2 OH- (aq) -> Cd(OH)2(s) + 2 e- Reduction:- 2NiO(OH)(s) + 2 H2O(l) + 2 e- -> 2Ni(OH)2(s) + 2 OH- (aq) Net:- Cd(s) + 2NiO(OH)(s) + 2 H2O(l) -> Cd(OH)2(s) + 2Ni(OH)2(s) Electrons moving from one place to another – this is electricity Numbers of electrons in oxidation and reduction must be same.

11. Contd… Alkaline Battery They all have the same voltage, because they’re all based on the same electrochemical cell

12. Contd… Reactions in Alkaline Batteries: Oxidation Zn(s) + 2 OH- (aq) -> Zn(OH)2(s) + 2 e- Reduction 2 MnO2(s) + H2O(l) + 2 e- -> Mn2O3(s) + 2 OH- (aq) Net Zn(s) + 2 MnO2(s) + H2O(l) -> Zn(OH)2(s) + Mn2O3(s)

13. BATTERIES ARRANGMENTS Serial arrangements :- In serial arrangements voltages add up Parallel arrangements:- In parallel arrangements currents add up.

14. WHY RECHARGEBLE BATTERIES? Purchasing rechargeable batteries saves money. Protects the environment They can be reused many times ,reducing operating cost.

15. WHEN NOT TO USE RECHARGEBLE BATTERY? They lose up to 1% of their power capacity per day. Emergency equipment (flashlights, radios, emergency medical devices, etc…). Low-power-use devices in difficult-to-access areas (field monitoring devices).

16. HOW IT IS RECHARGED? Recharge process is the reverse of the discharge process. An external source of direct electrical current supplies electrons to the anode and removes them from cathode, forcing the chemical reactions into reverse

17. REASONS OF BATTERY DEGRADATION Battery is connected to a device Battery is charged Battery is opened Battery is chemically activated

18. World of batteries

20. Lemon battery

21. Molten salt battery

22. Lead-acid battery

23. Lithium-sulfur battery

24. Lithium-titanate battery

25. Nickel hydrogen battery

26. Nickel-iron battery

27. Nickel-zinc battery

29. Need for battery exploring In excess of seven million barrels of gasoline are consumed by vehicles in the United States every day. As scientists race to find environmentally sound solutions to fuel the world's ever-growing transportation needs, battery researchers are exploring the promise of lithium-air battery technology.

30. The graph showing energy saved by each battery

31. Simple diagram showing mechanism in li-air battery

32. Mechanism in li-air battery Li-air batteries use a catalytic air cathode that supplies oxygen, an electrolyte and a lithium anode. The technology has the potential to store almost as much energy as a tank of gasoline, and will have a capacity for energy storage that is five to 10 times greater than that of Li-ion batteries, a bridge technology. That potential, however, will not be realized until critical scientific challenges have been solved.

33. Discharge capacity of li-air battery To 0.1A / g discharge rate of discharge, the discharge capacity is about 9000mAh / g. The previous lithium - air battery discharge capacity of only 700 ~ 3000mAh / g, can be said to achieve a substantial increase.The better than li-ion batteries(thinkpad t60 battery)

34. Focus on the reactions in li-air battery The project is confused on understanding more about how the chemical reaction of the battery works and investigating how to improve it. The research team is also working towards making a STAIR cell prototype suited, in the first instance, for small applications, such as mobile phones or MP3 players.

35. Thanks For Your Attention