Journal of The Electrochemical Society · 2008 · 168 citations · 29 references
EngineeringMaterials EngineeringMaterials ScienceAgingElectrochemical EngineeringElectrochemistryBattery MaterialsBattery TechnologyElectrochemical CellsElectrochemical Energy StorageEnergy StorageEnergy Storage MaterialsAnode PerformanceBattery AgingBattery DegradationCapacity FadeCapacity Fade ModelingCapacity FadingElectrochemical ModelingRate Capability
The authors cycled lithium‑ion pouch cells at five temperatures and every 100 cycles, then applied a simple physics‑based model to the rate‑capability data to estimate parameters describing capacity fade and the time‑dependent weight of active material. They found that loss of cyclable lithium dominates capacity decay in the first 200 cycles, while loss of active carbon becomes limiting thereafter, and that active‑material loss causes a sharp capacity drop at higher temperatures.
Lithium-ion pouch cells were cycled at five different temperatures (5, 15, 25, 35, and ), and rate capability studies were performed after every hundred cycles. The data were used with a simple physics-based model to estimate parameters that capture the capacity fade in the cell, with cycling. The weight of active material within each electrode was estimated as a function of time, using rate capability data at the C/33 rate. The C-rate for these cells is 1.656 A. The capacity fade due to the loss of active material and that due to the loss of cyclable lithium were quantified. It was found that while the loss of cyclable lithium is the limiting cause for the capacity decay of the cell during the first 200 cycles, the loss of active carbon, which is the anode material, becomes limiting for these cells. The loss of active material leads to a drastic decrease in cell capacity at higher temperatures.
29