A Stable Cross‐Linked Binder Network for SnO 2 Anode with Enhanced Sodium‐Ion Storage Performance

Stable binder network of anode is essential for the enhanced cycling performance of lithium ion battery electrode especially for SnO 2 anode, which has a big volume expansion/shrink during cycling. Here, we designed a cross‐linked polymer adhesive networks for SnO 2 anode of sodium‐ion battery by utilizing esterification reaction of PAA (Polyacrylic acid) and SS (soluble starch). The cross‐linked adhesive networks can effectively enhance the contact between conductive agent and SnO 2 particles, meanwhile serve as a buffer matrix of the expansion of SnO 2 during cycling and a protecting layer to reduce the contact of SnO 2 anode and electrolyte. As a result, a stable specific capacity of 370 mA h g −1 of the PAA‐SS@SnO 2 anode was obtained at a current density of 0.1 A g −1 after 150 cycles, while the specific capacity of PVDF@SnO 2 anode is only 200 mA h g −1 after 50 cycles. This cross‐linked adhesive networks present an effective and universal approach for application of pure SnO 2 as high performance anode of sodium ion batteries.