CASHIPS Achieves Progress in MoS2 Lithium Battery Electrode Materials

In MoS2 lithium battery electrode materials, Hefei Institutes of Physical Sciences of the Chinese Academy of Sciences (CASHIPS) has made a series of progress. Recently, the Bangchuan Zhao research group at the Functional Materials Research lab of the Institute of Solid State Physics, Chinese Academy of Sciences, has contributed progress in lithium-ion batteries (LIBs) electrode materials. The relevant research results were published in ChemElectroChem, Nanoscale, and Small.

Rechargeable lithium-ion batteries have important applications in electric vehicles, portable electronics, energy storage grids, and other fields and have received widespread attention. However, due to the low theoretical specific capacity (372mAh/g) of current commercial graphite anode materials, they cannot meet the needs for battery energy and power density. Aside from this, the extremely low working voltage of graphite makes the lithium battery hold a greater safety hazard when working. Therefore, exploring the anode materials with high safety, high specific capacity, high rate performance, and high cycle performance is a hot spot in the current research field of LIBs.

Compared with graphite, materials with a two-dimensional / quasi-two-dimensional crystal structure can be applied to lithium battery due to their relatively safe working voltage, large specific surface area, rich active sites, and fast ion/electron transfer capabilities. As a typical representative of 2D materials, molybdenum disulfide has a graphene-like layered structure and high theoretical specific capacity (669mAh/g). However, when MoS2 is used as a negative electrode material of LIBs, there are disadvantages such as poor rate performance due to poor material conductivity, and poor stability due to large volume changes during cycling. To solve these problems, the research group carried out modification research on molybdenum disulfide electrode materials and obtained MoS2 electrode materials with superior electrochemical performance.

MoS2-Ti3C2T SEM image

In response to the issue of poor conductivity of MoS2 electrode materials, the use of higher conductivity metal Co simplex and molybdenum disulfide composites has effectively improved the electrical conductivity and its electrochemical performance. Its capacity can still be maintained above 700mAh/g at a current density of 2A/g, the relevant results were published on ChemElectroChem.

To improve the cycle stability of the electrode, V4C3MXene and molybdenum disulfide were used for compounding, and a carbon coating process was used to prepare a V4C3-MXene/MoS2/C composite material. Since V4C3-MXene can effectively enhance the conductivity of the material and the stability of the electrode structure, carbon coating can further stabilize the structure of the material and increase the specific surface area of the material, thereby significantly improving the electrochemical performance of the electrode material. V4C3-MXene/MoS2/C electrode at 1A/g current density After 450 cycles, its capacity reaches about 600mAh/g. Even at a current density of 10A/g, the capacity is still maintained at about 500mAh/g. Related results by CASHIPS were published on Nanoscale.

Compared with the above 2H phase molybdenum disulfide, the 1T phase molybdenum disulfide owns advantages in conductivity and interlayer distance. However, the current preparation process of the 1T phase molybdenum disulfide is complicated, and the 1T phase MoS2 obtained is also unstable. Researchers synthesized a 1T-MoS2/C composite with 1T phase molybdenum disulfide and carbon composites with a small layer structure using a glucose-assisted hydrothermal method. CASHIPS research group published the related results on Small.