A Stable Cross-Linked Binder Network for SnO2 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 SnO2 anode, which has a big volume expansion/shrink during cycling. Here, we designed a cross-linked polymer adhesive networks for SnO2 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 SnO2 particles, meanwhile serve as a buffer matrix of the expansion of SnO2 during cycling and a protecting layer to reduce the contact of SnO2 anode and electrolyte. As a result, a stable specific capacity of 370 mA h g(-1) of the PAA-SS@SnO2 anode was obtained at a current density of 0.1 Ag-1 after 150 cycles, while the specific capacity of PVDF@SnO2 anode is only 200 mA hg(-1) after 50 cycles. This cross-linked adhesive networks present an effective and universal approach for application of pure SnO2 as high performance anode of sodium ion batteries.