Multifunctional cobalt heterostructure-graphite hybrid anode with superior cyclability for Li/Na-ion storage

Abstract

The research and development of novel materials for advanced lithium-ion (LIBs) and sodium-ion batteries (SIBs) are of paramount importance. Sulfide-based anode materials offer notable advantages, including high specific capacity and favorable cycling stability. The Co₃Sn₂S₂/Co₉S₈/Co (CSS-3) heterostructure was facilely synthesized via a vacuum thermal process and combined with graphite to form the CSS-3/G-15 % composite anode for both LIBs and SIBs. The uniform nano-heterostructure effectively mitigates volume expansion, promotes efficient electrolyte infiltration, and enhances ion and electron transport. Graphite incorporation prevents nanoparticle agglomeration, improving conductivity and providing a protective buffer to prevent degradation. In LIBs, CSS-3/G-15 % delivers a high specific capacity of 483.1 mA h g⁻¹ after 250 cycles at 0.1 A g⁻¹ and retains 529.2 mA h g⁻¹ after 1000 cycles at 1 A g⁻¹. At various current densities, it maintains impressive capacities (564.1 mA h g⁻¹ at 0.1 A g⁻¹ to 152.6 mA h g⁻¹ at 10 A g⁻¹). In SIBs, CSS-3/G-15 % shows stable performance, with a capacity of 181.7 mA h g⁻¹ after 500 cycles at 1 A g⁻¹. This approach offers new insights into anode material design, advancing both LIB and SIB technologies.