Week 1 Understanding Different Battery Chemistry
OBJECTIVE:
To 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 and to compare the differences between each type of Li+ion batteries based on their characteristics
THEORY:
The most popular technology of the battery sector currently is the lithium ion battery. Relative to other types of batteries, lithium ion batteries have better energy, power density and higher cycling ability. These qualities are extremely important in the use in modern applications like electrical and hybrid vehicles and most importantly energy storage systems which are used in the renewable energy applications. The lithium ion batteries chemistry is the same across the different lithium-ion battery types; during discharge, Lithium-ions are moved to the positive cathode from the negative anode through the organic electrolyte. The anodes in all various technologies of lithium ion are all made from graphite. The differences are the cathode which contains changing cobalt, nickel or manganese concentrations. All various cathode types allow high lithium insertion and intercalation levels which result in large energy storage quantities.
| S.No | Li-ion Cell Type |
Anode Reaction Charging:`->` Discharging:`larr` |
Cathode Reaction Charging:`->` Discharging:`larr` |
Overall Reaction Charging:`->` Discharging:`larr` |
| 1 |
LCO: Lithium Cobalt Oxide(LiCoO2) |
Graphite: `Li^(+) +e^(-)+C_6 harr LiC_6` |
`LiCoO_2 harr CoO_2+Li^+ + e^-` | `C_6 + LiCoO_2 harr LiC_6 + CoO_2` |
| 2 |
LMO: Lithium Manganese Oxide(LiMn2O4) |
Graphite: `Li^(+) +e^(-)+C_6 harr LiC_6` |
`LiMn_2O_4 harr Mn_2O_4 + Li^+ + e^-` | `C_6 + LiMn_2O_4 harr LiC_6 + Mn_2O_4` |
| 3 |
NCA: Lithium Nickel Cobalt Aluminium Oxide(LiNiCoAlO2) |
Graphite: `Li^(+) +e^(-)+C_6 harr LiC_6` |
`LiNiCoAlO_2 harr NiCoAlO_2 + Li^+ + e^-` | `C_6 + LiNiCoAlO_2 harr LiC_6 + NiCoAlO_2` |
| 4 |
NMC: Lithium Nickel Manganese Cobalt Oxide(LiNiMnCoO2) |
Graphite: `Li^(+) +e^(-)+C_6 harr LiC_6` |
`LiNiMnCoO_2 harr NiMnCoO_2 + Li^+ +e^-` | `C_6 + LiNiMnCoO_2 harr LiCo +NiMnCoO_2` |
| 5 |
LFP: Lithium Iron Phosphate(LiFePO4) |
Graphite: `Li^(+) +e^(-)+C_6 harr LiC_6` |
`LiFePO_4 harr FePO_4 + Li^+ + e^-` | `C_6 + LiFePO_4 harr FePO_4 + LiC_6` |
| 6 |
LTO: Lithium Titanate Oxide(Li2TiO3) |
Titanate: `Ti_5O_12 + 4Li^+ + 4e^(-) harr Li_4Ti_5O_12` |
`4LiMn_2O_4 harr 4Mn_2O_4 + 4Li^+ + 4e^-` | `LiTi_5O_12 + 4MnO_4 harr 4LiMn_2O_4+Ti_5O_12` |
1)LCO:
Very high specific energy, limited specific power. Cobalt is expensive. Serves as Energy Cell. Market share has stabilized.
Early version; no longer relevant.
2)LMO:
High power but less capacity; safer than Li-cobalt; commonly mixed with NMC to improve performance.
Less relevant now; limited growth potential.
3)NCA:
Shares similarities with Li-cobalt. Serves as Energy Cell.
Mainly used by Panasonic and Tesla; growth potential.
4)NMC:
Provides high capacity and high power. Serves as Hybrid Cell. Favorite chemistry for many uses; market share is increasing.
Leading system; dominant cathode chemistry.
5)LFP:
Very flat voltage discharge curve but low capacity. One of safest Li-ions.
Used for special markets. Elevated self-discharge.
Used primarily for energy storage, moderate growth.
6)LTO:
Long life, fast charge, wide temperature range but low specific energy and expensive.
Among safest Li-ion batteries.
Ability to ultra-fast charge; high cost limits to special application.
References:
https://www.youtube.com/watch?v=2tU10TiB8HU
https://sinovoltaics.com/learning-center/storage/lco-batteries/
https://pubs.rsc.org/en/content/articlepdf/2017/ra/c7ra10608d