JMCA Review: MXene-based materials help lithium-sulfur batteries

【Research Background】
       Energy crises and environmental pollution have prompted us to use clean energy sources such as wind, solar, biogas and nuclear power to generate electricity. However, due to the intermittent nature of these renewable energy sources, energy storage devices must be developed in order to use them effectively. In this context, electrochemical energy storage based on different redox reactions or Faraday effects is of great significance. Lithium-ion batteries (LIBs) are the most widely used commercial batteries, but there is still a large gap between optimal energy density and growing demand from advanced portable electronics, electric vehicles and fixed storage. Equipment market. At the same time, the relatively high cost and potential safety issues of lithium-ion batteries have also hampered their large-scale applications in electric vehicles. Therefore, exploring alternative high-energy electrochemical systems is of great significance for changing the way energy is stored.

[Introduction]
        Dr. Wang Ruihu from the Institute of Material Structure of the Chinese Academy of Sciences published a review article on MXene-engineered lithium-sulfur batteries on JMCA. The review details the development status of MXene-based lithium-sulfur batteries in recent years, and the common MXene-based lithium. The mechanism of the sulfur battery was summarized. Lithium-sulfur batteries are one of the most promising next-generation energy storage systems. In order to improve sulfur utilization and cycle stability, great efforts have been made to develop conductive nanostructures. MXenes are a class of two-dimensional transition metal carbides, nitrides and carbonitrides that have attracted widespread attention in recent years in terms of energy storage and conversion. This paper reviews recent advances in MXene-based materials in cathode, anode and separators for lithium batteries, highlighting the theoretical and experimental significance of high polarity and abundant surface chemistry in polysulfide capture. The development prospects and challenges of lithium-ion batteries are summarized. A new strategy for improving the electrochemical performance of lithium-ion batteries is proposed, which indicates the direction for the development of lithium-ion materials in high-energy lithium-ion batteries.

[Graphic introduction]

Figure 1 a) Energy density of various battery cells b) State of polysulfide in each charge and discharge phase.

Figure 2 Research status and basic status of Mxene-based lithium-sulfur battery

Figure 3 shows the basic structure of MXene-based lithium-sulfur battery

Figure 4, 5 Schematic diagram of surface functional groups and theoretical simulation of different surface functional groups

Table 1 is the related literature of the MXene-based lithium-sulfur battery cited herein. According to different material components, the author divides MXene-based lithium-sulfur materials into MXene-S binary system, MXene-C/S ternary system, MXene-polar material/S ternary system (metal sulfide, oxide and conductive). polymer).

[Article summary]
       This paper reviews the theoretical and experimental research progress of MXene-based materials in lithium batteries in recent years. MXene is used as an additive or a conductive substrate in the cathode, anode and separator, which greatly suppresses the shuttle effect and accelerates the utilization of sulfur. Therefore, high discharge capacity and rate performance can be obtained even in the case of high sulfur loading. And cycle stability. Despite considerable achievements in lithium-ion batteries, there are still some inherent problems that need to be further addressed to improve the electrochemical performance of lithium-ion batteries.

Literature link:
DOI: 10.1039/c9ta08600e

Source: WeChat public number MXene FrontierFigure