PPy‐encapsulated SnS2 Nanosheets Stabilized by Defects on TiO2 Support as Durable Anode Material for Lithium‐Ion Battery

PPy‐encapsulated SnS₂ nanosheets strongly anchored onto a hydrogen treated TiO₂ (H–TiO₂) support have been successfully prepared as an anode for LIBs. As demonstrated by first principles, theoretical calculations, and experimental results, the superior binding between SnS₂ and the H–TiO₂ support via abundant Ti–S bonding, which is reinforced by the oxygen vacancy, contributes to the unprecedented cycle stability.

Abstract

Nanostructured‐alloy‐type anodes have received great interest for high‐performance lithium‐ion batteries (LIBs). However, these anodes experience huge volume fluctuations during repeated lithiation/delithiation and are easily pulverized and subsequently form aggregates. Herein, an efficient method to stabilize alloy‐type anodes by creating defects on the surface of the metal oxide support is proposed. As a demonstration, PPy‐encapsulated SnS₂ nanosheets supported on defect‐rich TiO₂ nanotubes were produced and investigated as an anode material for LIBs. Both experimental results and theoretical calculations demonstrate that defect‐rich TiO₂ provides more chemical adhesions to SnS₂ and discharge products, compared to defect‐poor TiO₂, and then effectively stabilizes the electrode structure. As a result, the composite exhibits an unprecedented cycle stability. This work paves the way to designing durable and active nanostructured‐alloy‐type anodes on oxide supports.

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