Abstract
? 2022 Elsevier B.V.Although the utilization of conducting polymers in silicon anodes as both a conductive agent and binder is extremely attractive, key challenges exist in maintaining constant electric connectivity with silicon, especially during long-term cycling. In addition to the in-situ formation of polyaniline (PANI) encapsulating silicon nanoparticles (SiNPs) inside, herein PANI is also used as a three-dimensional (3D) bridge to interconnect the outside carbon nanotubes functionalized with carboxyl groups (CNFs-COOH) via electrostatic attraction and π-π conjugation. Further improvements in Li-ion diffusion kinetics and cycling properties can be achieved by low-temperature sintering the double-protected SiNPs without destruction of the 3D PANI conductive skeleton. Such a novel composite (i.e. Si@C/PANI-CNT) with a 3D hierarchically interconnected architecture containing 52 wt% SiNPs delivers a high discharge capacity of 879 mAh g?1 at 0.5 A g?1 with a capacity loss of 0.084% per cycle after 500 cycles. Increasing the current density to 1 A g?1, no big change in the 500th discharge capacity (817 mAh g?1) is found and the specific capacity still stabilizes around 605 mAh g?1 over 1000 cycles.
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