Understanding Different Battery Chemistry

Q. Prepare a table that includes materials & chemical reactions occurring at the anode and cathode of LCO, LMO, NCA, NMC, LFP, and LTO type of lithium-ion cells.

A lithium-ion battery is a type of rechargeable battery. Lithium-ion batteries are commonly used for portable electronics and electric vehicles and are growing in popularity for military and aerospace applications.

In the batteries, lithium ions move from the negative electrode through an electrolyte to the positive electrode during discharge, and back when charging. Li-ion batteries use an intercalated lithium compound as the material at the positive electrode and typically graphite at the negative electrode.

Electrochemistry

The working principle behind the working of a cell can be explained using electrochemistry. The reactants in the electrochemical reactions in a lithium-ion cell are materials of anode and cathode, both of which are compounds containing lithium atoms.

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 (together with the cathode material) in a reduction half-reaction. The electrolyte and external circuit provide conductive media for lithium ions and electrons, respectively, but do not partake in the electrochemical reaction. During discharge, electrons flow from the negative electrode (anode) towards the positive electrode (cathode) through the external circuit. The reactions during discharge lower the chemical potential of the cell, so discharging transfers energy from the cell to wherever the electric current dissipates its energy, mostly in the external circuit.

During charging these reactions and transports go in the opposite direction: electrons move from the positive electrode to the negative electrode through the external circuit. To charge the cell the external circuit has to provide electric energy. This energy is then stored as chemical energy in the cell (with some loss, e. g. due to coulombic efficiency lower than 1).

Both electrodes allow lithium ions to move in and out of their structures with a process called insertion (intercalation) or extraction (deintercalation), respectively.

Electrolyte

An electrolyte is a substance that produces an electrically conducting solution when dissolved in a polar solvent, such as water. The dissolved electrolyte separates into cations and anions, which disperse uniformly through the solvent. Electrically, such a solution is neutral.

Liquid electrolytes
Liquid electrolytes in lithium-ion batteries consist of lithium salts, such as LiPF_6, LiBF_4 or LiClO_4 in an organic solvent, such as ethylene carbonate, dimethyl carbonate, and diethyl carbonate. A liquid electrolyte acts as a conductive pathway for the movement of cations passing from the negative to the positive electrodes during discharge.
Conductivities of liquid electrolyte at room temperature (20 °C (68 °F)) are in the range of 10 mS/cm, increasing by approximately 30–40% at 40 °C (104 °F) and decreasing slightly at 0 °C (32 °F).
The combination of linear and cyclic carbonates (e.g., ethylene carbonate (EC) and dimethyl carbonate (DMC)) offers high conductivity and solid electrolyte interphase (SEI)-forming ability.

Solid electrolytes
The advanced battery technologies involve using a solid as the electrolyte material. The most promising of these are ceramics.
Solid ceramic electrolytes are mostly lithium metal oxides, which allow lithium-ion transport through the solid more readily due to the intrinsic lithium. The main benefit of solid electrolytes is that there is no risk of leaks, which is a serious safety issue for batteries with liquid electrolytes.
Solid ceramic electrolytes can be further broken down into two main categories, ceramic and glassy.
Ceramic solid electrolytes are highly ordered compounds with crystal structures that usually have ion transport channels.
Glassy solid electrolytes are amorphous atomic structures made up of similar elements to ceramic solid electrolytes but have higher conductivities overall due to higher conductivity at grain boundaries.

Both glassy and ceramic electrolytes can be made more ionically conductive by substituting sulfur for oxygen. The larger radius of sulfur and its higher ability to be polarized allow higher conductivity of lithium. This contributes to the conductivities of solid electrolytes that are nearing parity with their liquid counterparts, with most on the order of 0.1 mS/cm (ms/cm=millisiemens per centimeter) and the best at 10 mS/cm.

Lithium-Ion Batteries
Sl. No.	Types of Lithium-Ion Batteries	Material		Chemical Reaction	Application
		Anode	Cathode
1	Lithium Cobalt Oxide(LiCoO2)-LCO	Graphite	Cobalt oxide	The positive electrode (cathode) half-reaction `CoO_2+Li^++e^(-)harrLiCoO_2` The negative electrode (anode) half-reaction `LiC_6harrC_6+Li^++e^-` Full reaction (left`to`right:charging & right`to`left discharging) `LiC_6+CoO_2harrC_6+LiCoO_2`	Mobile phones, tablets, laptops, cameras
2	Lithium Nickel Manganese Cobalt Oxide (LiNiMnCoO2)-NMC	Graphite	Nickel Manganese Cobalt Oxide	The positive electrode (cathode) half-reaction `NiMnCoO_2+Li^++e^(-)harrLiNiMnCoO_2` The negative electrode (anode) half-reaction `LiC_6harrC_6+Li^++e^-` Full reaction (left`to`right:charging & right`to`left discharging) `LiC_6+NiMnCoO_2harrC_6+LiNiMnCoO_2`	E-bikes, medical devices, EVs, industrial
3	Lithium Iron Phosphate(LiFePO4)-LFP	Graphite	Iron Phosphate	The positive electrode (cathode) half-reaction `FePO_4+Li^++e^(-)harrLiFePO_4` The negative electrode (anode) half-reaction `LiC_6harrC_6+Li^++e^-` Full reaction (left`to`right:charging & right`to`left discharging) `LiC_6+FePO_4harrC_6+LiFePO_4`	Portable and stationary needing high load currents and endurance
4	Lithium Nickel Cobalt Aluminum Oxide (LiNiCoAlO2)-NCA	Graphite	Nickel Cobalt Aluminum Oxide	The positive electrode (cathode) half-reaction `NiCoAlO_2+Li^++e^(-)harrLiNiCoAlO_2` The negative electrode (anode) half-reaction `LiC_6harrC_6+Li^++e^-` Full reaction (left`to`right:charging & right`to`left discharging) `LiC_6+NiCoAlO_2harrC_6+LiNiCoAlO_2`	Medical devices, industrial, electric powertrain (Tesla)
5	Lithium Manganese Oxide (LiMn2O4)-LMO	Graphite	Manganese Oxide	The positive electrode (cathode) half-reaction `Mn_2O_4+Li^++e^(-)harrLiMn_2O_4` The negative electrode (anode) half-reaction `LiC_6harrC_6+Li^++e^-` Full reaction (left`to`right:charging & right`to`left discharging) `LiC_6+Mn_2O_4harrC_6+LiMn_2O_4`	Power tools, medical devices, electric powertrains
6	Lithium Titanate (Li2TiO3)-LTO	Titanate (Li_2TiO_3)	Manganese Oxide or NMC	The positive electrode (cathode) half-reaction `Mn_2O_4+Li^++e^(-)harrLiMn_2O_4` The negative electrode (anode) half-reaction `Li_2TiO_3harrTiO_3+2Li^++2e^-` Full reaction (left`to`right:charging & right`to`left discharging) `Li_2TiO_3+2Mn_2O_4harrTiO_3+2LiMn_2O_4`	UPS, electric powertrain (Mitsubishi i-MiEV, Honda Fit EV), solar-powered street lighting

Lithium Cobalt Oxide(`LiCoO_2`)-LCO

Lithium Cobalt Oxide: LiCoO2 cathode (~60% Co), graphite anode Short form: LCO or Li-cobalt. Since 1991
Voltages	3.60V nominal; typical operating range 3.0–4.2V/cell
Specific energy (capacity)	150–200Wh/kg. Specialty cells provide up to 240Wh/kg.
Charge (C-rate)	0.7–1C, charges to 4.20V (most cells); 3h charge typical. Charge current above 1C shortens battery life.
Discharge (C-rate)	1C; 2.50V cut off. Discharge current above 1C shortens battery life.
Cycle life	500–1000, related to depth of discharge, load, temperature
Thermal runaway	150°C (302°F). Full charge promotes thermal runaway
Applications	Mobile phones, tablets, laptops, cameras
Comments 2019 update:	Very high specific energy, limited specific power. Cobalt is expensive. Serves as Energy Cell. Market share has stabilized. Early version; no longer relevant.

Lithium Manganese Oxide (`LiMn_2O_4`)-LMO

Lithium Manganese Oxide: LiMn2O4 cathode. graphite anode Short form: LMO or Li-manganese (spinel structure) Since 1996
Voltages	3.70V (3.80V) nominal; typical operating range 3.0–4.2V/cell
Specific energy (capacity)	100–150Wh/kg
Charge (C-rate)	0.7–1C typical, 3C maximum, charges to 4.20V (most cells)
Discharge (C-rate)	1C; 10C possible with some cells, 30C pulse (5s), 2.50V cut-off
Cycle life	300–700 (related to the depth of discharge, temperature)
Thermal runaway	250°C (482°F) typical. High charge promotes thermal runaway
Applications	Power tools, medical devices, electric powertrains
Comments 2019 update:	High power but less capacity; safer than Li-cobalt; commonly mixed with NMC to improve performance. Less relevant now; limited growth potential.

Lithium Nickel Manganese Cobalt Oxide (`LiNiMnCoO_2`) — NMC

Lithium Nickel Manganese Cobalt Oxide: LiNiMnCoO2. cathode, graphite anode Short form: NMC (NCM, CMN, CNM, MNC, MCN similar with different metal combinations) Since 2008
Voltages	3.60V, 3.70V nominal; typical operating range 3.0–4.2V/cell, or higher
Specific energy (capacity)	150–220Wh/kg
Charge (C-rate)	0.7–1C, charges to 4.20V, some go to 4.30V; 3h charge typical. Charge current above 1C shortens battery life.
Discharge (C-rate)	1C; 2C possible on some cells; 2.50V cut-off
Cycle life	1000–2000 (related to the depth of discharge, temperature)
Thermal runaway	210°C (410°F) typical. High charge promotes thermal runaway
Cost	~$420 per kWh (Source: RWTH, Aachen)
Applications	E-bikes, medical devices, EVs, industrial
Comments 2019 update:	Provides high capacity and high power. Serves as Hybrid Cell. Favorite chemistry for many uses; market share is increasing. Leading system; dominant cathode chemistry.

Lithium Iron Phosphate(`LiFePO_4`) — LFP

Lithium Iron Phosphate: LiFePO4 cathode, graphite anode Short form: LFP or Li-phosphate Since 1996
Voltages	3.20, 3.30V nominal; typical operating range 2.5–3.65V/cell
Specific energy (capacity)	90–120Wh/kg
Charge (C-rate)	1C typical charges to 3.65V; 3h charge time typical
Discharge (C-rate)	1C, 25C on some cells; 40A pulse (2s); 2.50V cut-off (lower than 2V causes damage)
Cycle life	2000 and higher (related to the depth of discharge, temperature)
Thermal runaway	270°C (518°F) Very safe battery even if fully charged
Cost	~$580 per kWh (Source: RWTH, Aachen)
Applications	Portable and stationary needing high load currents and endurance
Comments 2019 update:	Very flat voltage discharge curve but low capacity. One of the safest Li-ions. Used for special markets. Elevated self-discharge. Used primarily for energy storage, moderate growth.

Lithium Nickel Cobalt Aluminum Oxide (`LiNiCoAlO_2`) — NCA

Lithium Nickel Cobalt Aluminum Oxide: LiNiCoAlO2 cathode (~9% Co), graphite anode Short form: NCA or Li-aluminum. Since 1999
Voltages	3.60V nominal; typical operating range 3.0–4.2V/cell
Specific energy (capacity)	200-260Wh/kg; 300Wh/kg predictable
Charge (C-rate)	0.7C charges to 4.20V (most cells), 3h charge typical, fast charge possible with some cells
Discharge (C-rate)	1C typical; 3.00V cut-off; high discharge rate shortens battery life
Cycle life	500 (related to the depth of discharge, temperature)
Thermal runaway	150°C (302°F) typical, High charge promotes thermal runaway
Cost	~$350 per kWh (Source: RWTH, Aachen)
Applications	Medical devices, industrial, electric powertrain (Tesla)
Comments 2019 update:	Shares similarities with Li-cobalt. Serves as Energy Cell. Mainly used by Panasonic and Tesla; growth potential.

Lithium Titanate (`Li_2TiO_3`) — LTO

Lithium Titanate: Cathode can be lithium manganese oxide or NMC; Li2TiO3 (titanate) anode Short form: LTO or Li-titanate Commercially available since about 2008.
Voltages	2.40V nominal; typical operating range 1.8–2.85V/cell
Specific energy (capacity)	50–80Wh/kg
Charge (C-rate)	1C typical; 5C maximum, charges to 2.85V
Discharge (C-rate)	10C possible, 30C 5s pulse; 1.80V cut-off on LCO/LTO
Cycle life	3,000–7,000
Thermal runaway	One of the safest Li-ion batteries
Cost	~$1,005 per kWh (Source: RWTH, Aachen)
Applications	UPS, electric powertrain (Mitsubishi i-MiEV, Honda Fit EV), solar-powered street lighting
Comments 2019 update:	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 a special application.

References

1. https://en.wikipedia.org/wiki/Lithium-ion_battery

2. https://batteryuniversity.com/learn/article/types_of_lithium_ion