An advanced LiCrTiO4@C cathode towards hybrid Mg-Li ion batteries with ultrastable cycling stability

•LiCrTiO4 nanoparticles with carbon layer (LCTOC) are successfully prepared by sol–gel method.•Reversible capacity of 114.3 mAh/g is achieved at 1 A/g over 2500 cycles, indicating its ultrastable cycling stability.•Morphology and structure of LCTOC are maintained perfectly during long-term cycling.•Such a superior capacity of LCTOC is attributed to the improved conductivity and ion-diffusion rate. Hybrid magnesium-lithium ion batteries (HMLBs) merge Li+ faster kinetics with dentrite-free and low-cost Mg anode and are arousing widespread concern. It is regrettable that its development is limited by the lack of advanced electrode materials. Herein, LiCrTiO4 nanoparticles with/without carbon layer (LCTOC/LCTON) are successfully prepared by sol–gel method and used as cathodes for HMLBs. Compared with LCTON, LCTOC not only exhibits a high reversible capacity (139.3 mAh/g at 100 mA/g after 100 cycles), but also possesses an excellent rate performance (123.1 mAh/g at 500 mA/g). Notably, a reversible capacity of 114.3 mAh/g at 1 A/g has been achieved over 2500 cycles, indicating an ultrastable cycling stability. The enhanced electrochemical performance of LCTOC is attributed to the improved conductivity and ion diffusion rate, and decreased polarization value induced by the carbon coating layer with a higher surface area. In addition, the ion storage mechanism of LCTOC is explored by ex-situ tests. The morphology and structure of LCTOC have been maintained perfectly during the long-term charge–discharge process, indicating a highly structural stability and reversibility. This study exhibits a promising application of LCTOC in the fabrication of advanced HMLBs.