Simulation of Li-ion Cells by Dualfoil Model under Constant-Resistance Load

The Dualfoil model is used to simulate the electrochemical behavior and temperature rise for MCMB/LiCoO2 Li-ion cells under constant-resistance load operation, approaching a short-circuit condition. Electrolyte and solid surface concentration profiles of lithium-ion across the cell at various time scales are developed and analyzed to explain the lithium-ion transport limitations. Sensitivity simulative tests are conducted using selected values of the heat-transfer coefficient, lithium-ion diffusion coefficient in the solution and solid phases, electrode kinetic rate constants, and film resistance. Radial mass transport of lithium from the center of the pore to the pore wall (in the CoO2) has been added to the model to describe better current limitations at very high discharge currents. The results show that excessive overheating in batteries can result under conditions approaching short circuit.