A graphite functional layer covering the surface of LiMn2O4 electrode to improve its electrochemical performance

•We first introduce sputtering a graphite layer covering the surface of LMO electrode.•Improved electrochemical properties are possessed at 55 °C by as-modified LMO cathode.•The graphite layer acts as conductive media, as well as a beneficial barrier at the interface.

Here, we first report the introduction of sputtering a graphite layer covering the surface of the as-fabricated LiMn2O4 cathode to form a protective layer as a solution to solve the rapid capacity fading of LiMn2O4-based lithium ion battery at elevated temperature. Compared with the rapid capacity fading of the bare LiMn2O4 cathode (LMO), the graphite layer modified cathode (G-LMO) possesses excellent cyclic performance at 55 °C. It maintains 92% of initial discharge capacity even after 500 cycles at 1C. TEM images show that the surface of the bare LiMn2O4 particles in LMO sample is damaged while G-LMO withstands Mn leaching induced by HF corrosion under the protection of graphite layer.

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