Week 1 Understanding Different Battery Chemistry

WEEK 1 CHALLENGE

Objective 1: - To prepare a table that includes materials and chemical reactions occurring at the anode and cathode of LCO, LMO, NCA, NMC, LFP and LTO type of Lithium-ion cell.

Procedure: -

Introduction:

Lithium-ion cells or battery is a rechargeable or secondary type of battery. It is used in portable devices such as cell phones, laptops etc. Due to its overall characteristics, it has found its place in automotive and aerospace industry. It was first developed by Akira Yoshino (Japanese chemist) from the research done by John Goodenough, Stanley Whittingham, Rachid Yazami and Koichi Mizushima.

Construction:

The Lithium-ion battery majorly consists of four parts

1. Electrodes (Cathode and anode)
2. Electrolyte
3. Separator
4. Current Collector

Working:

The reactants in the electrochemical reactions in a lithium-ion cell are materials of anode and cathode, both contains lithium atom compounds. During discharge an oxidation half reaction at the anode produces positively charged lithium ions and negatively charged electrons. The oxidation half reaction may also produce uncharged material that remains at the anode. Lithium ions move through the electrolyte, electrons move through the external circuit and then they recombine at the cathode in a reduction half reaction.

The electrolyte and the external circuit provide conductive media for lithium ions and electrons respectively, but do not take part in the electrochemical reaction. During charging these reactions and transports go in the opposite direction (electrode move from positive electrode to the negative electrode through the external circuit). To charge the cell the external circuit has to provide electric energy which is converted and stored as chemical energy.

Types of lithium-ion batteries and their reactions are given as follows

SI.NO	Type of Li-ion battery	Cathode	Anode	Electrolyte	Chemical Reaction
1.	Lithium Cobalt Oxide (LCO)	LiCoO2	LiC6	LiPF6 in Ethylene Carbonate	Anode: LixC6 => xLi+ + xe- + C6 Cathode: Li1-xCoO2+ xLi+ + xe- => LiCoO2 Redox Reaction: C6 + LiCoO2 <=> LiC6 + CoO2
2.	Lithium Manganese Oxide	LiMn2O4	LiC6	LiPF6 in Ethylene Carbonate	Anode: LixC6 => xLi+ + xe- + C6 Cathode: Li1-xMn2O4+ xLi+ + xe- => LiMn2O4 Redox Reaction: C6 + LiMn2O4 <=> LiC6 +Mn2O4
3.	Lithium Nickel Cobalt Aluminium Oxide (NCA)	LiNiCoAlO2	LiC6	LiPF6 in Ethylene Carbonate	Anode: LixC6 => xLi+ + xe- + C6 Cathode: Li1-xNiCoAlO2+ xLi+ + xe- => LiNiCoAlO2 Redox Reaction: C6 + LiNiCoAlO2 <=> LiC6 + NiCoAlO2
4.	Lithium Nickel Manganese Cobalt Oxide (NMC)	LiNi0.8Mn0.1Co0.1O2	LiC6	LiPF6 in Ethylene Carbonate	Anode: LixC6 => xLi+ + xe- + C6 Cathode: LiNi0.8Mn0.1Co0.1O2 + xLi+ + xe- => LiNi0.8Mn0.1Co0.1O2 Redox Reaction: C6+LiNi0.8Mn0.1Co0.1O2 <=> LiC6 + NiCoAlO2
5.	Lithium Iron Phosphate (LFP)	LiFePO4	LiC6	LiPF6 in Ethylene Carbonate	Anode: LixC6 => xLi+ + xe- + C6 Cathode: Li1-xFePO4+ xLi+ + xe- => LiFePO4 Redox Reaction: C6 + LiFePO4 <=> LiC6 + FePO4
6.	Lithium Titanium Oxide (LTO)	LiMn2O4	Li4Ti5O12	LiPF6 in Ethylene Carbonate	Anode: Li4Ti5O12 => Ti5O12+ 4Li+ +4e- Cathode: 4Li1-xMn2O4+ 4Li+ + 4e- => 4LiMn2O4 Redox Reaction: Li4Ti5O12+4Mn2O4 <=> 4LiMn2O4 +Ti5O12

Objective 2: Compare the differences between each type of Li- ion batteries based on their characteristics

Parameters	LCO (Lithium Cobalt Oxide)	LMO (Lithium Manganese Spinel)	LFP (Lithium Iron Phosphate)	NCA (Lithium Nickel Cobalt Aluminium)	NMC (Lithium Nickel Manganese Cobalt Oxide)
1.Specific Energy	High	Moderate	Low	High	High
2.Specific Power	Moderate	High power/Less capacity	High	Moderate	Moderate
3.Performance	Moderate	Low	Moderate	Moderate	Moderate
4.Life Span	Short	Short	Large	Moderate	Moderate
5.Cost	Expensive	Low	Low	High	Low
6.Safety	Less	Moderate	Safest of all	Less	Moderate