Enhanced Electrochemical Performance of Sb₂O₃ as an Anode for Lithium-Ion Batteries by a Stable Cross-Linked Binder

A binder plays an important role in lithium-ion batteries (LIBs), especially for the electrode materials which have large volume expansion during charge and discharge. In this work, we designed a cross-linked polymeric binder with an esterification reaction of Sodium Carboxymethyl Cellulose (CMC) and Fumaric Acid (FA), and successfully used it in an Sb₂O₃ anode for LIBs. Compared with conventional binder polyvinylidene fluoride (PVDF) and CMC, the new cross-linked binder improves the electrochemical stability of the Sb₂O₃anode. Specifically, with CMC-FA binder, the battery could deliver ~611.4 mAh g^−1 after 200 cycles under the current density of 0.2 A g^−1, while with PVDF or CMC binder, the battery degraded to 265.1 and 322.3 mAh g^−1, respectively. The improved cycling performance is mainly due to that the cross-linked CMC-FA network could not only efficiently improve the contact between Sb₂O₃ and conductive agent, but can also buffer the large volume charge of the electrode during repeated charge/discharge cycles.