Abstract:
We present a numerical simulation of thermo-electrochemical processes of a Li-ion battery. Mathematical model of thermo-electrochemical processes is described on a microscopic scale and contains nonlinear equations for concentration, potential and temperature. A Li-ion battery consists of three subdomains: two electrodes and the electrolyte. On the interface of electrodes and electrolyte there are Lithium ions intercalation and deintercalation processes which are described by the Butler-Volmer nonlinear equation. The main problem of numerical implementation is the discontinuity of concentration and potential at the interface of the subdomains. To take into account the discontinuity, we use mixed finite elements in spatial approximation of a coupled system: discontinuous Galerkin elements for concentration and potential and continuous Galerkin elements for temperature. The time approximation is performed using a fully implicit scheme. The nonlinear system of equations obtained by approximation is solved by the Newton method.
Keywords:Li-ion battery, thermo-electrochemical process, Butler–Volmer equation, finite element method.