Week 1 Understanding Different Battery Chemistry
Q1.Prepare a table which includes materials & chemical reactions occurring at the anode and cathode of LCO, LMO, NCA, NMC, LFP and LTO type of lithium ion cells.Give your detailed explanation on it.
LITHIUM COBALT OXIDE (LiCoO2)
The most popular lithium-ion cells use a carbon (C) anode and a lithium cobalt oxide cathode (LiCoO2). In fact, the lithium cobalt oxide battery was the world's first lithium-ion battery. Cobalt and oxygen combine to form layers of octahedral cobalt oxide structures, which are separated by lithium sheets. When charging and discharging, it's critical that this structure allows the cobalt ions to shift their valence states from Co+3 to Co+4 (lose and acquire a negatively-charged electron).
Lithium is oxidised at the anode. Lithium ions and electrons are liberated from the carbon:
At the cathode, lithium-ions are absorbed by the lithium dioxide, and the electrode is reduced as it also receives the electrons from the circuit:
LITHIUM IRON PHOSPHATE (LiFePO4)
A lithium iron phosphate battery cell looks like a lithium cobalt oxide battery cell. The anode is still made of graphite, and the electrolyte is same. The lithium cobalt dioxide cathode has been replaced with lithium iron phosphate, which is more stable. A fully charged cell's iron phosphate (FePO4) cathode contains no lithium or iron ions. Without appreciably modifying the iron phosphate framework, lithium ions can intercalate into or out of the cathode material through well-defined tunnels in its structure.
DURING DISCHARGE
At the anode, lithium is oxidised. Lithium ions are released from the carbon, along with electrons:
At the cathode, lithium ions are absorbed by the lithium dioxide, and the electrode is reduced as it also receives the electrons from the circuit:
3. LITHIUM MANGANESE OXIDE (LiMn2O4)
A cathode constructed of lithium-manganese spinel (Li+Mn3+Mn4+O4) is used in this type of lithium battery. Spinel is a mineral that has a unique AB2O4 structure. The spinel structure is extremely thermally stable, which increases the battery's safety. It also improves ion flow inside the electrolyte and reduces internal resistance, both of which contribute to a battery's power loss over time. While this form of lithium battery has a high discharge and recharge rate (owing to the cathode's spinel shape), it has a lesser capacity and a shorter lifespan.
4.LITHIUM NICKEL MANGANESE COBALT OXIDE (LiNiMnCoO2 or NMC)
When nickel and cobalt are reintroduced into the mix, things change slightly again. Nickel has a high specific energy and, when combined with the manganese spinel's stable structure, produces a battery that also benefits from the manganese spinel structure (low internal resistance, high charging rate, good stability and safety).The cathode in these batteries is usually made up of one-third nickel, one-third manganese, and one-third cobalt, but the proportions might vary depending on the manufacturer's proprietary formulations. Power tools, electric vehicles, and medical gadgets all use these batteries.
Q2.Compare the differences between each type of Li+ion batteries based on their characteristics
| Cell Chemestries | Specific Energy | Specific Power | Safety | Performance | Life Span | Cost |
| NCA | High | High | Medium | Good | Very high | High |
| NMC | High | Good | Good | Good | Good |
Low |
| LMO | Medium | Good | Good | Low | Medium | Medium |
| LTO | Low | Good | High | High | High | High |
| LFP | Medium | Good | High | Good | High | Low |
Most preffered cell chemistries is NMC in Electric Vehicle applications due to high specific power ,energy and low Cost with good life cycles.