On the study of cyclic plasticity behaviour of primary electrode particle for lithium-ion battery

The mechanical failure of battery electrode, caused by the cyclic diffusion-induced stress, is generally thought to be a direct reason leading to the loss of capacity and deterioration of performance for Li-ion battery. In the present work, the cyclic plasticity behaviour of primary electrode particle under electrochemical-mechanical condition is evaluated by using the Linear Matching Method (LMM). The coupled diffusion-stress analysis of electrode particle during lithiation-delithiation process is performed with the developed finite element subroutines as the groundwork for the subsequent cyclic plasticity assessment. The shakedown boundaries are established for electrode particle considering the variation of particle diameter by means of the LMM. ABAQUS full cyclic incremental analysis is employed to verify the applicability and accuracy of the obtained boundary. Two types of failure mechanisms known as low-cycle fatigue and ratcheting are investigated for particle subjected to loading history out of shakedown boundary. Steady state cycle analysis is conducted to study the generation of plastic strain range of particle under certain electrochemical-mechanical condition and the corresponding low-cycle fatigue damage is assessed. Different forms of ratcheting boundaries for electrode particle with various dimensions are created and the influences of cyclic current density and mechanical load on cyclic plasticity limits are clarified. The established critical failure diagrams will offer the instructional information regarding the design of electrode material in microscale within designated electrochemical condition