Li Ion batteries: Difference between revisions

From wikiluntti
Line 12: Line 12:
* Full charge voltage is 4.2 V, which is the maximum voltage
* Full charge voltage is 4.2 V, which is the maximum voltage


Chenistry:
Chemistry:
* Lithium Cobalt Oxide (LiCoO2):  nominal voltage of 3.6V and is known for its high energy density.
* Lithium Cobalt Oxide (LiCoO2):  nominal voltage of 3.6V and is known for its high energy density.
* Lithium Manganese Oxide (LiMn2O4): a nominal voltage of 3.7V and offer thermal stability compared to LiCoO2  
* Lithium Manganese Oxide (LiMn2O4): a nominal voltage of 3.7V and offer thermal stability compared to LiCoO2  
* Lithium Nickel Manganese Cobalt Oxide (NMC): a nominal voltage of 3.6V or 3.7V and provide a good balance of energy density and power capability.
* Lithium Nickel Manganese Cobalt Oxide (NMC): a nominal voltage of 3.6V or 3.7V and provide a good balance of energy density and power capability.
* Lithium Iron Phosphate (LiFePO4): a nominal voltage of about 3.2V with excellent safety characteristics and long cycle life.
* Lithium Iron Phosphate (LiFePO4): a nominal voltage of about 3.2V with excellent safety characteristics and long cycle life.
Over upper limit (maximum voltage) battery will cause electrolyte breakdown and thermal runaway.
Below lower Limit (2.5V) the battery’s chemistry may change irreversibly.
State of charge (SOC) and maximum voltage relation.


== 21700 cells ==
== 21700 cells ==


== Spot welding ==
== Spot welding ==

Revision as of 10:35, 10 August 2025

Introduction

1865 / 18650 cells

Diameter is 18 mm and length 65.0 mm.

Voltage

Note that the chemistry changes and thus these value might be a bit different. Be careful.

  • Discharge cutoff voltage (the low voltage limit) is around 2.0V to 2.5V
  • Nominal voltage is (usual) 3.6 V or 3.7 V.
  • Full charge voltage is 4.2 V, which is the maximum voltage

Chemistry:

  • Lithium Cobalt Oxide (LiCoO2): nominal voltage of 3.6V and is known for its high energy density.
  • Lithium Manganese Oxide (LiMn2O4): a nominal voltage of 3.7V and offer thermal stability compared to LiCoO2
  • Lithium Nickel Manganese Cobalt Oxide (NMC): a nominal voltage of 3.6V or 3.7V and provide a good balance of energy density and power capability.
  • Lithium Iron Phosphate (LiFePO4): a nominal voltage of about 3.2V with excellent safety characteristics and long cycle life.

Over upper limit (maximum voltage) battery will cause electrolyte breakdown and thermal runaway.

Below lower Limit (2.5V) the battery’s chemistry may change irreversibly.

State of charge (SOC) and maximum voltage relation.

21700 cells

Spot welding