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

[Display omitted] •A stretchable SiOx/carbon integrated anode was prepared by using triblock copolymer elastomer SBAS and SWCNTs.•The rational molecular structure of SBAS has been designed and synthesized via RAFT emulsion polymerization.•Ester bonds formed between SiOx and SBAS enhances interface adhesion.•π-π conjugation between SBAS and SWCNTs maintains stability of the conductive network during stretching.•The high-capacity electrode after 10% strain exhibits satisfactory capacity and an excellent capacity retention of 91.6% after 100 cycles. 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.