Week 1 Understanding Different Battery Chemistry

1. Introduction to lithium-ion cells and their types :

Lithium-ion batteries are the best and most commonly found batteries that are used in various field of application due to their robust and most often dry designs that have high energy densities & specific energy values. They are relatively expensive to make depending upon the type but they operate well under loads and are capable of bearing high temperatures and sometimes even structural load.
Lithium-ion is named for its active materials; the words are either written in full or shortened by their chemical symbols. For example, Lithium Iron Phosphate(LiFePO4) is one of the most common Li-ion battery types and is commonly abbreviated as LFP.

Types of Li-ion cells/chemistry - 

1. Lithium Cobalt Oxide(LiCoO2) — LCO
2. Lithium Manganese Oxide (LiMn2O4) — LMO
3. Lithium Nickel Manganese Cobalt Oxide (LiNiMnCoO2) — NMC
4. Lithium Iron Phosphate(LiFePO4) — LFP
5. Lithium Nickel Cobalt Aluminum Oxide (LiNiCoAlO2) — NCA
6. Lithium Titanate (Li2TiO3) — LTO
   
   
   

Chemical reactions - 

S No.

Battery

Full Form

Cathode

Anode

Electrolyte

Reaction at anode

Reaction at cathode

Redox reaction

1	LCO	Lithium Cobalt  Oxide	LiCoO2	LiC6	LiPF6	LixC6 → xLi+ + xe- + C6	Li1-xCoO2 + xLi+ + xe- → LiCoO2	C6 + LiCoO2 ↔ LiC6 + CoO2
2	LMO	Lithium Manganese Oxide	LiMn2O4	LiC6	LiPF6	LixC6 → xLi+ + xe- + C6	Li1-xMn2O4 + xLi+ + xe- → LiMn2O4	C6 + LiMn2O4 ↔ LiC6 + Mn2O4
3	NCA	Lithium Nickel Cobalt Aluminium Oxide	LiNiCoAlO2	LiC6	LiPF6	LixC6 → xLi+ + xe- + C6	Li1-xNiCoAlO2 + xLi+ + xe- → LiNiCoAlO2	C6 + LiNiCoAlO2 ↔ LiC6 + NiCoAlO2
4	NMC	Lithium Nickel Manganese Cobalt Oxide	LiNi0.8Mn0.1Co0.1O2	LiC6	LiPF6	LixC6 → xLi+ +xe- + C6	Li1-xNi0.8Mn0.1Co0.1O2 + xLi+ + xe- → LiNi0.8Mn0.1Co0.1O2	C6 + LiNi0.8Mn0.1Co0.1O2 ↔ LiC6 + Ni0.8Mn0.1Co0.1O2
5	LFP	Lithium Iron Phosphate	LiFePO4	LiC6	LiPF6	LixC6 → xLi+ + xe- + C6	Li1-xFePO4 + xLi+ + xe- → LiFePO4	C6 + LiFePO4 ↔ LiC6 + FePO4
6	LTO	Lithium Titanium Oxide	LiMn2O4	Li4Ti5O12	LiPF6	Li4Ti5O12 → Ti5O12 + 4Li+ + 4e-	4Li1-xMn2O4 + 4Li+ + 4e- → 4LiMn2O4	Li4Ti5O12 + 4Mn2O4 ↔ 4LiMn2O4 + Ti5O12

2. Type of Li+ion batteries 

• LCO – Lithium cobalt battery: These batteries are manufactured using lithium carbonate and cobalt. They have a very high specific energy and thus are used in electronics. They have short battery life and low specific power.
  
  Chemical formulae - LiCoO₂
  Invention – 1991
  Energy density – 150-200 Wh/kg
  Cycle life – 500 – 1000
  Charge (C-rate)- 0.7 to 1C , 4.20v
  Anode – LiaC6 (graphite Carbone)
  Cathode – LibCoO2 (cobalt oxide)
  Carrier – Li+
  Used: electronic devices and older or cheaper laptop batteries

Advantages-

1. High energy density
2. Long runtime

 Disadvantages

1. High loads heat the battery
2. Low discharge current
3. Limited safety
4. Affected by cycling and aging
5. High resistance and unserviceable

• NMC – Lithium Manganese Cobolt Oxide: These are also known as lithium manganate spinel batteries(Li-NMC, NMC, or NCM). Moli energy manufactured the first commercial lithium-ion cells using lithium manganese oxide as the cathode material in 1996. These batteries are safer and have higher stability towards high-temperature operations. They are mostly found and used in medical applications and tool
  
  

  Chemical formulae – LiNi_xMn_yCo_zO₂
  Invention – 1980
  Energy density – 150-200 Wh/kg
  Anode – LiaC6 (Multi-material mixture)
  Cathode – LibCoO2
  Carrier – Li+
  Used: mostly found in mobile electronics

Advantages:

1. Long life
2. Low cost
3. High density in a small package
4. Cathode contains the most current

Disadvantages:

1. Based on the materials added the disadvantages vary
2. The growth or shrinkage of batteries
3. Poor stability
4. Low voltage output

• LFP – Lithium Iron Phosphate: THere phosphate is used as the cathode, and is also often called li-phosphate batteries. They have low resistance qualities which improve thermal stability and safety making them more durable and perform for higher life cycles at a cheaper cost. They form a carbon nanotube type of structure to store energy.
  
  Chemical formulae – LiFePO₄
  Cycles – 2000 to 12000
  Invention – John B Goodenough 1950
  Energy density – 90-160 Wh/kg
  Charge – 3.2V or 610 C/g
  Anode – graphite carbon in metallic backing
  Cathode – polyanion class of cathode (C-LiFePO4)
  Carrier – Li+
  Specific capacity – 170mA
  Used: it is mostly seen in solar energy-related applications and EVs.

Advantages:

1. Low cost
2. Low toxicity
3. Well defined performance
4. Stability

Disadvantages

1. More stable at fully charged conditions
2. Low nominal voltage (3.2v)
3. High Self-discharge

• LTO – Lithium Titanate: These are often known as Li-titanate. These batteries have a growing number of uses because of their superior nano-technology. These batteries recharge very quickly, these batteries are often coupled and used with other batteries and are mostly used in electric vehicles. The problem with such batteries is that they have very low intrinsic voltages and energy density. They are also used in aerospace applications and they can be made smaller than other batteries and thus are used in several backup and data protection applications.
  
  Chemical formulae – Li₂TiO₃
  Invention – 2005 by altairnano
  Energy density – 117 Wh/L
  Specific energy – 60 to 110 Wh/Kg
  Cycles – 6000 to 10000
  Anode – Lithium titanate nanocrystals
  Cathode – Layers of molten carbon
  Charge – 2.4 V
  Carrier – Li+
  Used: military and aerospace

Advantages:

1. Safety and stability during use
2. Highly reliable
3. Fast charging and performance
4. Long life cycle
5. Temperature resistance

Disadvantages

1. Low energy density
2. Cost
3. Excessive R&D required before use

• NCAs – Lithium Nickel Cobalt Aluminum Oxide: Lithium nickel cobalt aluminum oxide batteries are being used in electric vehicles and grid storage. They have very little use in general consumer electronics and are mostly used for automobiles or defense-related industries. They are of high energy with a long life span. They however lack in terms of safety. Thus, they require sophisticated monitoring and regulating control systems.
  
  Chemical formulae - LiNi_0.8Co_0.15Al_0.05O₂
  Invention – 1999
  Anode – graphite and hard carbons
  Cathode – lithium, nickel, cobalt, aluminum cations
  Carrier – any of the cations
  Charge – 3.6 to 4 V
  Used: used greatly by Panasonic and tesla

Advantages:

1. Cost
2. Storage
3. Stability and safety

Disadvantages

1. Deuteriation and breakdown
2. Overcharge thermal runaway

• LMO – Lithium manganese oxide battery: This is structured as a spinel inside the battery to improve the flow of ions. It includes lithium saults that serve as an organic solvent and acts like a bridge. These types of batteries are generally not rechargeable. They are designed to be very flexible and can be used in a wide range of applications
  
  Chemical formulae – LiMnO2
  Invention – 1996
  Energy density – 150-200 Wh/kg
  Cycle life – 500 – 1000
  Charge (C-rate)- 1C-10C , 3.5 V
  Anode – Lithium
  Cathode – Manganese
  Carrier – Li+
  Used: Non-rechargeable batteries for small-scale electronics.

Advantages:

1. Low cost
2. Easy to manufacture
3. High-temperature range
4. Stable and safe

Disadvantages

1. Not rechargeable
2. Although safe may explode
3. Due to ease of manufacturing. Fakes and low-quality products are made
4. And if harmful when exposed to ultrasonic waves.
   
   

3. Comparison of Li+ion batteries