Molybdenum disulfide (MoS2) has attracted significant attention in lithium battery electrode materials due to its unique layered structure and semiconductor properties. As a research direction for MoS2 in lithium battery applications, its theoretical specific capacity reaches 670 mAh/g, far exceeding the 372 mAh/g of commercial graphite anodes, making it a candidate material for next-generation high-energy-density lithium batteries. However, the intrinsic conductivity of MoS2 is relatively low (bandgap approximately 1.2-1.8 eV), and volume expansion during charge-discharge cycles reaches approximately 103%, limiting cycle life — this is the core challenge that current research efforts focus on addressing.

MoS2 Layered Structure and Lithium Storage Mechanism

MoS2 belongs to the transition metal dichalcogenide family, composed of S-Mo-S trilayers stacked together with weak van der Waals forces between layers, with an interlayer spacing of approximately 0.62 nm. During charge-discharge processes, lithium ions can intercalate between layers to form LixMoS2 intercalation compounds. According to the conversion reaction mechanism, when discharged to 0.01 V, MoS2 decomposes into Mo nanoparticles and Li2S, which reversibly recombine during charging — this process contributes the majority of the reversible capacity. A 2014 study published in Nature Communications demonstrated that the lithium-ion diffusion barrier of monolayer MoS2 is only 0.25 eV, significantly lower than 0.48 eV for bulk material, indicating that nanostructuring can effectively enhance ion transport kinetics.

Three Technical Pathways for Conductivity Improvement

**Carbon-based composites** combine MoS2 with graphene, carbon nanotubes, or porous carbon to leverage the high-conductivity network of carbon materials to compensate for the charge transport bottleneck of MoS2. Experimental data shows that MoS2/graphene composite electrodes retain 82% capacity after 100 cycles at 100 mA/g, while pure MoS2 electrodes retain only 35%. Carbon compositing also mitigates volume expansion stress during charge-discharge cycling.

**Elemental doping** introduces cobalt, nickel, iron, and other transition metals to substitute molybdenum sites, or nitrogen/sulfur-doped carbon substrates, to tune the electronic structure and reduce the bandgap. First-principles calculations indicate that Co doping narrows the MoS2 bandgap from 1.8 eV to below 0.5 eV, increasing carrier concentration by two orders of magnitude.

**Nanostructure design** includes fabricating ultrathin nanosheets, hollow spheres, and three-dimensional hierarchical structures to shorten lithium-ion diffusion paths and increase active site density. When MoS2 nanosheet thickness decreases from 50 nm to 3 nm, the electrolyte contact area increases 4-5 times, and rate performance maintains 420 mAh/g reversible capacity even at 2 A/g high current density.

Challenges for Practical Application

Although laboratory data is encouraging, MoS2 still faces barriers to commercialization as a lithium battery electrode material. First, the initial Coulombic efficiency is typically low, ranging from 60-75%, due to SEI film formation and irreversible conversion reactions. By comparison, commercial graphite anodes achieve initial Coulombic efficiency above 90%. Second, regarding electrolyte compatibility, the cycling stability of MoS2 in carbonate electrolytes is significantly inferior to ether-based electrolytes, but the latter has a narrower oxidation window, limiting compatibility with high-voltage cathodes.

From an industry perspective, the global lithium battery anode material market was valued at approximately 240 billion yuan in 2023 and is projected to exceed 700 billion yuan by 2030. Currently, artificial graphite dominates commercial anodes, accounting for over 80% market share. Industrialization of MoS2 and other high-capacity anode materials requires simultaneously addressing material preparation costs, electrochemical stability, and scalable manufacturing processes.

Technology Development Trends

Current research is advancing in the following directions: first, phase engineering — using 1T-phase MoS2 (metallic phase) to replace the 2H phase (semiconductor phase), with 1T-phase conductivity approximately 10^7 times higher than 2H; second, interface modification — coating MoS2 surfaces with carbon or TiO2 protective layers to suppress dissolution of conversion products; third, coupling with lithium-sulfur batteries — leveraging MoS2's catalytic conversion capability for lithium polysulfides to simultaneously improve both cathode and anode performance.

Overall, the application of molybdenum disulfide in lithium battery electrode materials remains in the transitional stage from laboratory to pilot scale. Conductivity improvement requires coordinated optimization across material microstructure, composite strategies, and electrode fabrication processes. With the maturation of nano-fabrication technologies and growing demand from the new energy industry for high-energy-density batteries, engineering applications of MoS2-based electrode materials are expected to achieve substantial breakthroughs within the next 5-8 years.

Tags: molybdenum disulfide lithium battery electrode materials MoS2 负极材料 conductivity electrode materials nanostructure carbon composite specific capacity