Because of its lightweight, out-standing energy density, and well cycling stability, lithium-ion batteries (LIBs) are widely utilized in portable devices and electric vehicles (EVs). Researchers have intensively studied low-cost, high-storage capacity, and safe electrode materials for LIBs. Graphite is the most widely used commercial anode material, but its low theoretical capacity (372 mA h g-1) restricts its application in high-energy-density devices. Lithium-titanium–based insertion materials possess excellent cycle life and high rate capability but suffer from low capacity (< 200 mA h g-1) and high electrical resistivity. Silicon-based alloy materials and transition-metal-oxide-based conversion materials exhibit high capacity over 1000 mA h g-1, but severe volume changes during charging/discharging processes lead to fast capacity fading.
Herein, we report a Mo-Fe-mixed Keplerate polyoxometalate (POM), a kind of Fullerene-like metal oxide clusters which was synthesized through a simple solution process as anode material for LIBs. Because of various oxidation states of Mo and Fe , the multiple redox centers within Mo-Fe-mixed POM during charge-discharge processes result in high capacity and excellent cycling stability. These results demonstrate that Fullerene-like Mo-Fe-mixed POM is a promising anode material for LIBs.