Week 1 Understanding Different Battery Chemistry

Li-ion

1. Which discharging, negative electrode gives up electrons & gets oxidized.
2. Which charging, negative electrode accepts electrons & get reduced.
3. Also known as reduction-Oxidation or redox reactions.

• Operate by shuttling Li-ions to the anode host structre on charge .
• Transporting the same ions across the porous separator via the electro lgte to the cathode host structure on discharge.
• During discharge,positively charged ions or cations move through the electrolyte toward the positve electrode,
• and negatively charged ions or anions if present move through the electrolyte towards charged the negative electrode.

Lithum ion Cathode (Positive Materials)

1. Layered Transition metal oxides, spinels and olivines.
2. Metal oxides highest capacity but cost & safety concerns (NCA,NMC,LCO)
3. Spinels high power density but poor electronic conductivity & structural stability (LMO,LTO)
4. Olivines Better safety & long life but low capacity & voltage (life Po4)

Lithum ion Anode (Negative Material)

1. Carbon based anode graphite & hard carbon.
2. Low cost stable and high specific capacity.
3. issue lithium plating when the potential of the anode because.
4. excessively low li-ion can plate out as metallic lithium on the surface of the anode.
5. Dendeite formation capacity loss.

Trade-off among five main lithium battery technologies

1. Lithium -nickel- cabalt aluminum(NCA)

.Specific energy

. Cost

. Life span

. Performance

. Safety

. Specific power

2.Lithium- nickel-manganese-cobalt (NMC)

. Specific energy

. Cost

. Life span

. Performance

. Safety

. Specific power

3.Lithium-mangnese-spinel(LMO)

. Specific energy

. Cost

. Life span

. Performance

. Safety

. Specific power

4. Lithium titanate (LTO)

. Specific energy

. Cost

. Life Span

. Performance

. safety

. Specific power

5.Litim-iron phosphate (LFP)

. Specific enery

. Cost

. Life span

. Performance

. safety

. Specific power

Lithium ion cell elements

• Anode,Cathode, Electrolyte,Separator & Casing
• Choice of material for electrodes
• Vast majority use graphitic carbon anode
• Operating temperature,life cycles, energy density etc.