Direct imaging of dynamic heterogeneous lithium–gold interaction at the electrochemical interface during the charging/discharging processes
Jiaxin Mao, Guopeng Li, Dongwei Xu, Rui Hao
Abstract
optical microscopic approach that allows direct imaging of Li-Au interaction with high spatiotemporal and chemical resolution has been developed. Through this approach, a two-step Li-Au alloying process that exhibits interesting complementary spatiotemporal evolution paths has been discovered. The alloying process regulates the nucleation of further Li deposition, while the Li nucleation sites generate pores on the electrode film. After several cycles, film rupture occurs due to the generation of an increased number of pores, thus explaining the previously unclear mechanism of poor cycling stability. We have also elucidated the deterioration mechanism of silver electrodes: the growth of defect pores in size, independent of the alloying process. Overall, this new imaging approach opens up an effective and simple way to monitor the dynamic heterogeneity of metal-metal interaction at the electrochemical interface, which could provide helpful insight for designing high-performance batteries.