Battery knowledge · Aging and degradation
Structural degradation
Changes in the crystal structure of a positive material as it cycles: layered oxides can rearrange into spinel or rock-salt phases at the surface, with nickel ions migrating into lithium sites. The new phases block lithium transport and raise resistance. [1]
- Also called
- phase transformation, cation mixing
Example
Aging and degradation: an example situation
Capacity loss and resistance rise can have different causes; a film-growth curve cannot identify both.
Read Structural degradation alongside High-nickel cathode in this context. A layered oxide with 80 % or more nickel, such as NMC811 or NCA. Nickel raises capacity and lowers cobalt content, but the material is less thermally stable, more sensitive to moisture and ages faster at high voltage.
Use in Lemonergy
Separate mechanisms, observations and fitted models.
This is a reference concept. No executable Lemonergy block has been verified for this term.
References & further reading
Technical references
- Lithium ion battery degradation: what you need to know
Physical Chemistry Chemical Physics · 2021
Technical reference · Degradation mechanisms, modes, operational effects and their interactions.