A good explanation of why lithium ion batteries lose capacity over their cycle life is that components of the electrolyte oxidize at the cathode under high voltage and high temperature conditions which then are reduced at the anode side and eventually block-off the porosity and ionic conduction deeper into the anode material which then results in lithium metal plating and shutting down of the cell.
This seems a more likely cause and effect than my explanation for the lithium ion lifecycle test below thinking the failure was due to pulverization of the cathode material since that would in turn cause oxygen release and gassing into a puffy cell which did not happen, so i think electrolyte reduction and coating on the anode would better explain the sudden loss of capacity.
A very interesting theory and technique for measurement of electrolyte degradation are explained in the video below by Jeff Dahn of Dalhousie University.
- by English for Science
- 5 months ago
- 8,213 views