Reconciling Capacity Degradation for Sodium-Ion Pouch Cell by Practical Electrocatalytic-Driven Compensation Strategy
Jianguo Li, Youzhong Dong, Xin Wang, Yunbo Li, Qinghua Fan, Jiantie Xu, Haijiao Xie, Quan Kuang, Yanming Zhao
Abstract
Irreversible active sodium loss (ASL) is widely regarded as a pivotal factor influencing the cycle life and energy density of sodium-ion full cells. Introducing practical electrocatalyst-driven compensation strategies for ASL and other multiple benefits in sodium-ion batteries (SIBs) is a tireless pursuit of researchers. Herein, Pd atoms were used to catalytically drive the decomposition of Na 2 O to compensate for ASL in Na 3 (Mn 0.8 Fe 0.2 ) 2 (PO 4 )(P 2 O 7 )//hard carbon (NMFPP//HC) pouch cells. This compensation strategy not only replenished the sodium inventory loss caused by SEI and Mn 2+ shuttle effect but also constructed a NaF-rich rigid CEI layer. The dissolution and shuttling of Mn 2+ can be significantly inhibited by this kind of rigid NaF-CEI layer. Finally, incorporating 8 wt % currently modified precondition with NMFPP cathode, the energy density of the corresponding pouch cell (NMFPP-PNO//HC) presents an essential improvement of 29% relative to the unmodified system. This study proposes a universal approach for ASL compensation and electrode stabilization in the design of high-performance SIBs.