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Spinel Li4Mn5O12 has been of economical and academic interest as cathode material for 3 V lithium-ion batteries(LIBs) since the 1990s.Recent studies also demonstrate that the increase of upper cut-off voltage to 5.0 V can significantly promote the specific capacity and the average operating voltage thus enabling its possibility to be used in 4 V LIBs.It is cost-effective and environmentally benign,shows structural stability without suffering from Jahn-Teller distortion due to the tetravalent oxidation state of Mn ion.However,the undesirable decomposition reactions during high-temperature calcination result in the difficulty of fabricating stoichiometric Li4Mn5O12 compounds.Meanwhile,the high capacity led by the enlarged voltage window is combined with fast capacity fading due to the poor reversibility of oxygen redox.In this review,the understanding of the relationship between structure and stochiometric chemistry of Li4Mn5O12 is discussed and the ways to improving its electrochemical performance are summarized.Our focus is its recent developments of being used as high voltage cathode or “additive” for layered cathodes.At last,we also provide our perspectives on this material regarding to the target of enabling its application in 4 V LIBs.