Pre-embedded lithium strategy improves the electrochemical performance of V2CMXene

【Research Background】

       In recent decades, lithium-ion batteries have attracted widespread attention and made great progress. However, LIBs are facing problems such as high prices, scarce resources, and safety. It is necessary to develop an alternative energy storage device. Due to the high theoretical capacity of divalent ions of magnesium ions, the rich magnesium content of the earth, and the extremely high safety of magnesium electrodes, rechargeable magnesium ion batteries have become a new generation of new batteries that are promising to replace lithium ion batteries. Despite the many advantages of magnesium electrodes, the development of magnesium ion batteries is still constrained by electrode materials and electrolytes.

[Achievement Profile]

        Recently, the  team of Professor Fan Lizhen from the Advanced Energy Materials Research Institute of the Institute of Advanced Materials Technology, University of Science and Technology Beijing published a research paper in the internationally renowned academic journal Small , entitled Prelithiated V2C MXene: A High-Performance Electrode  for Hybrid Magnesium / Lithium-Ion Batteries by Ion Cointercalation. Thearticle reports a high-performance magnesium-lithium composite battery based on pre-embedded lithium V2C MXene, which provides a new idea for future battery design.

[Picture and text guide]

Figure 1 is a schematic diagram of pre-inserted lithium V2C, SEM TEM analysis and related physical characterization of V2AlC and V2C

Figure 2 shows the relevant lithium-ion battery performance test. The most outstanding one is its excellent cycle stability.

Figure 3 shows the relevant performance test of the magnesium-lithium composite ion battery. It can be seen that such a composite battery can improve the stability of the battery.

[Summary of this article]

       In summary, this work demonstrates a simple and fast self-discharge method to prepare prelithiated V2C MXene with high ion storage capacity. The Li + pre-inserted layer provides an alternative lithium source for SEI formation, which can effectively alleviate lithium consumption, expand the interlayer distance of MXenes, and provide a rich active site and fast channel for ion transport. In addition, in situ XRD and in situ XPS characterization validated the Mg / Li co-intercalation reaction mechanism. The battery chemistry discussed and studied opens up new ways to improve the initial Coulomb efficiency of LIB electrodes and provides new ideas for the application of MXene-based materials as electrode candidates for high-performance rechargeable MLIBs.

Literature link

DOI: 10.1002 / smll.201906076