Novel hybrid binder mixture tailored to enhance the electrochemical performance of SbTe bi-metallic anode for sodium ion batteries

Abstract

In developing high performance sodium ion batteries, synergism between all components of the battery is important, particularly the role of binder is of great importance given the increase in volume expansions as a result of larger ionic radius of sodium ion. In this work, hybrid binder mixture was tailor made to sustain key reactions that lead to stable kinetics of the cell and increase the initial capacities in the process, without having to choose strategies which compromise the capacities like increase in FEC or carbon support matrix contents. The novel hybrid binder mixture of PAA: PVDF delivers enhanced initial capacities, superior cyclabilities and rate capabilities with the cells with SbTe-C40 and 5% FEC added electrolyte exhibiting high initial capacities of 364 mAh g−1 and 393 mAh g−1 for hybrid binder mixtures of Ver(7:3) (70 wt% PAA: 30 wt% PVDF) and Ver(5:5) (50 wt% PAA: 50 wt% PVDF), respectively, and 94.7% and 91.3% of their respective second cycle capacities were retained after 500 cycles at a high c-rate of 1000 mA g−1. © 2020