Stretchable high-capacity SiOx/carbon anode with good cycle stability enabled by a triblock copolymer elastomer

Abstract

Stretchable lithium-ion batteries (LIBs) are key technologies for flexible/wearable electronics, yet low energy density and poor stability remain challenges. Here, we proposed a high-capacity stretchable SiOx/C anode with good stability, using triblock copolymer elastomer matrix poly(styrene-b-(n-butyl acrylate)-b-styrene) (SBAS) to provide stretchability (up to 1160%) and mechanical support. SBAS cross-links with SiOx to enhance interface adhesion. Single-walled carbon nanotubes (SWCNTs) were introduced to construct long-range conductive network and further improve mechanical strength. Besides, SBAS has strong π-π conjugation with SWCNTs, which keeps stability of the conductive network of integrated electrodes during stretching. When the deformation increases to 15%, resistance of the electrode only increases by 1.3 times. After 50 stretching-releasing cycles at 10% strain, it maintains a high capacity of 1442 mAh g−1 at 150 mA g−1. After 100 cycles, it achieves an excellent capacity retention of 91.6%. This work provides new insight into the development of high-capacity anodes for stretchable LIBs.