Stress evolution in SiO electrodes for lithium-ion batteries during electrochemical cycling

SiO is a promising anode material for lithium-ion batteries. To explore the mechanism through which SiO electrodes operate, we have measured the real-time stress evolution in SiO electrodes during electrochemical cycling. Results show that a compressive stress of 91 MPa is developed during the first lithiation process, moreover, the stress is not fully recovered during the following delithiation process. Upon delithiation, the compressive stress rapidly reduces to about 20 MPa then saturates to a quasi-plateau stress curve. The stress behavior was related to the porous nature of the SiO electrode. The comparison between the potential and the stress evolution, along with morphology changes of the electrode, suggests that stress-induced particle rearrangement leads to the increasing delithiation capacity and the stress mitigation during the initial cycling.