ZIF-67-derived Co/N-C hollow nanocubes@SiO2 composite for high performance lithium-ion batteries

In this work, a composite Co/N-C@SiO2 with hollow nanocube structure is successfully prepared using ZIF-67 as a sacrificial template, addressing the issue of poor conductivity and significant volume expansion of SiO2. The described preparation method is efficient, economical and environmentally friendly. The composite contains N-doped carbon and Co0 nanoparticles generated in-situ from ZIF-67, which significantly improves the electrical conductivity of SiO2. The composite's rich cavity structures act as a buffer for SiO2 volume expansion during the charging-discharging process, resulting in improved cycling stability. Additionally, the unique hollow structure of the active material can enhance lithium-ion transport kinetics, shorten the ion transport path, and improve the lithium storage performance. The Co/N-C@SiO2 composite exhibits excellent rate and long cycling performance, with a reversible capacity of 479 mA h g−1 at a current density of 5 A g−1, and retaining 337 mA h g−1 after 700 cycles. [Display omitted] •The Co/N-C@SiO2 composite with hollow nanocubic structure has been synthesized utilizing ZIF-67 as sacrificial template.•Electrochemical performance of the composite is enhanced by the N-doped carbon and cobalt nanoparticles derived from ZIF-67.•High rate performance and excellent cycling stability, 337 mA h g-1 discharging capacity at 5 A g-1 after 700 cycles.