Enhanced electrochemistry of AlPO4 nano-layer-wrapped LiMn2O4 cathode material for an aqueous rechargeable lithium-ion battery

Cubic spinel LiMn 2 O 4 (LMO) nanomaterial was synthesized by the solid-state method via double-step calcinations process, and AlPO 4 (AlP) nano-layer is used to modify the spinel LiMn 2 O 4 (LMO) electrode material, which was manufactured using a chemical deposition solution process. The cubic spinel crystal structure of LiMn 2 O 4 wrapped by the AlPO 4 layer was verified by structural analysis (XRD) and morphological analysis (FESEM and HRTEM). TEM result indicates that the AlPO 4 nano-layer does not affect the bulk structure of pristine LiMn 2 O 4 material. The electrochemical results demonstrated that the AlPO 4 -wrapped LiMn 2 O 4 (AlP-LMO) cathode can still deliver its initial discharge capacity of 147.6 mAh g −1 , whereas the pristine LiMn 2 O 4 cathode has an initial discharge capacity of 116.4 mAh g −1 at 0.5 C rate. AlPO 4 nano coating can effectively prevent the increase of the charge transfer resistance during charge–discharge process and improve the electrochemical performance of AlP-LMO electrode due to the protective nature of AlPO 4 nano-layer. Graphic Abstract