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The hybrid magnesium-lithium-ion batteries (MLIBs) combining the dendrite-free deposition of the Mg anode and the fast Li intercalation cathode are better alternatives to Li-ion batteries (LIBs) in large-scale power storage systems. In this article, we reported hybrid MLIBs assembled with the VO cathode, dendrite-free Mg anode, and the Mg-Li dual-salt electrolyte. Satisfactorily, the VO cathode delivered a stable plateau at about 1.75 V, and a high specific discharge capacity of 244.4 mA h g. To the best of our knowledge, the VO cathode displays the highest energy density of 427 Wh kg among reported MLIBs in coin-type batteries. In addition, an excellent rate performance and a wide operating temperature window from 0 to 55 °C have been obtained. The combination of VO cathode, dual-salt electrolyte, and Mg anode would pave the way for the development of high energy density, safe, and low-cost batteries.

Rechargeable magnesium batteries (RMBs) have been regarded as one of the promising electrochemical energy storage systems to complement Li‐ion batteries owing to the low‐cost and high safety characteristics. However, the various challenges including the sluggish solid‐state diffusion of highly polarizing Mg2+ ions in hosts, and the formation of blocking layers on Mg metal surface have seriously impeded the development of high‐performance RMBs. In order to solve these problems toward practical applications of RMBs, a tremendous amount of work on electrodes and electrolytes has been conducted in the last few decades. Creative optimization strategies including the modification of cathodes and anodes such as shielding the charges of divalent Mg2+, expanding the layers of host materials, and optimizing the interface of electrode–electrolyte are raised to promote the technology. In this review, the detailed description of innovative approaches, representative examples, and facing challenges for developing high‐performance electrodes are presented. Based on the review of these strategies, guidelines are provided for future research directions on improving the overall battery performance, especially on the electrodes.

Magnesium batteries are promising energy storage systems because of the advantages of low raw material cost, high theoretical capacity, and high operational safety properties. However, the divalent Mg2+ has a sluggish kinetic in the cathode materials which resulted in poor electrochemical performance. Many strategies were adopted to improve the mobility of Mg2+ in the host structures. In this paper, we report on the optimization of chain-like structure VS4@reduced graphene oxide (VS4@rGO) through expanding interchain distance to increase the ion diffusivity. By combining theoretical calculations and experimental investigations, the expansion of interchain distance and reversible intercalation of MgCl+ are revealed. With the fast kinetics of MgCl+ (instead of Mg2+) intercalation into expanded VS4@rGO, higher capacity of 268.3 mA h g–1 at 50 mA g–1 and better rate capability of 85.9 mA h g–1 at 2000 mA g–1 have been obtained. In addition, the expanded VS4@rGO framework shows a high specific capacity of 147.2 mA h g–1 after 100 cycles and a very wide operating temperature range (−35 to 55 °C). The high discharge capacity, excellent rate capability, and broad temperature adaptability demonstrate promising application of VS4@rGO in magnesium batteries.

We designed the Bi nanorods encapsulated in N-doped carbon tubes with hollow structure, which can limit the large volume change during the potassiation process. The composite exhibits superior electrochemical performance as anode for K-ion batteries.