Integration of urchin-like MnCo₂O₄@C core–shell nanowire arrays within porous copper current collector for superior performance Li-ion battery anodes

Spinel MnCo₂O₄ is a promising energy storage candidate as anode materials in lithium-ion batteries owing to synergistic effects of two intrinsic solid-state redox couples. However, low conductivity, poor rate capacity and rapid capacity fading have seriously impaired its practical applications. To overcome the inferiorities, urchin-like MnCo₂O₄@C core–shell nanowire arrays have been fabricated directly within a porous copper current collector via a facile hydrothermal method followed by a chemical vapor deposition carbonization process. In a typical nanowire, the core is composed of interconnected MnCo₂O₄ nanoparticles and the shell shows as a thin amorphous carbon layer. The integrated MnCo₂O₄@C/Cu structure could act as working anodes without using additives or polymer binders. While MnCo₂O₄@C/Cu possesses slightly longer Li-ion insertion/desertion pathway than that of MnCo₂O₄/Cu, the carbon shell could effectively prevent the pulverization of MnCo₂O₄ and lower down charge transfer resistance and actively participate in Li-ion cycles. The rearrangement of carbon atoms during lithiation/delithiation cycling could inhibit the formation of passive solid electrolyte interphase films. As a result, the MnCo₂O₄@C/Cu electrode presents superior rate capacity (600 mAh·g⁻¹ at 1 A·g⁻¹) and better stability (797 mAh·g⁻¹ after 200 cycles at 100 mA·g⁻¹). The excellent reversible Li ion storage capacity, cycling stability and rate capacity endow MnCo₂O₄@C/Cu great potential as stable and high output integrated anode materials in Li-ion batteries.