Reviving bulky MoS2 as an advanced anode for lithium-ion batteries

Abstract

Bulky MoS₂ obtained from molybdenite is an inexpensive and naturally abundant product with high intrinsic Li storage capacity originating from the Li storage capabilities of its Mo atoms and active S element. How to release the intrinsic capacity of bulky MoS₂ is of great interest but has not been explored to date. Herein, we developed a surface-modification triggered self-assembling process to construct a robust 3D bulky MoS₂@C/RGO composite. The adjacent N-doped amorphous carbon layer and outer RGO component not only can help immobilize the active Mo atoms and polysulfide ions during extended cycles but can also help release volumetric strain and accelerate electron transportation. Furthermore, the hierarchical 3D porous structure is beneficial for electrolyte penetration and Li ion diffusion. As a result, the intrinsic Li storage capability of bulky MoS₂ is readily released. It delivers the discharge capacity of 1189 mA h g⁻¹ at 200 mA g⁻¹ after 100 cycles. At the higher current density of 1 A g⁻¹, the reversible capacity of 770 mA h g⁻¹ is still maintained. Further examination of the MoS₂-PDA-GO30//LiCoO₂ full cells suggests that the as-obtained sample (1750 W h kg⁻¹) is promising to achieve practical applications. This study may shed some light on the direct usage of bulky MoS₂ powder as a high-performance LIB anode. Moreover, the synthesis strategy proposed herein may be a versatile protocol for the rational design of other bulky materials, such as Si and metal oxides, for high-performance energy storage devices.