Multi-dimensional hybrid heterostructure MoS2@C nanocomposite as a highly reversible anode for high-energy lithium-ion capacitors

A high-performance lithium-ion capacitor was constructed using nano-hybrid graded hollow sphere composite electrode material (MoS2@C) synthesized with sucrose and sodium molybdate, with the aid of nitric acid and citric acid monohydrate. [Display omitted] •The composite electrode can produce self-buffering characteristics and formed Mo-O-C bond.•Oxygen vacancies and lower energy barrier is conducive to the diffusion of Li+.•The synergistic effect of oxygen deficiency and carbon creates a high pseudocapacitance.•The cathode has a huge specific surface area (2017.13 m2 g−1) and abundant micropores (0.5–0.65 nm).•The LIC system achieves the efficient matching, while showing ultra-high power-energy density. Lithium-ion capacitors (LICs) are a new generation of hybrid energy storage devices, and there is room for improvement in power characteristic, energy density and cycling life. This paper proposes a facile and high-efficiency strategy for the preparation of high-performance MoS2 based anodes, here we have successfully synthesized a multi-dimensional hybrid heterogeneous composite material (MoS2@C) in which nanoparticles, nanoflakes and hollow nanospheres coexist. The strong adhesion of the Mo-O-C bond formed between MoS2 and carbon ensures favorable structural integrity, while the architecture made of nanoflakes reduces the diffusion distance of Li+. In addition, the voids of the hollow structure can alleviate the volume change during repeated Li+ intercalation/de-intercalation processes and ensure good contact between the material and the electrolyte solution. Moreover, due to the confinement effect of the hollow structure and carbon and the introduction of oxygen vacancies, excellent rate performance is achieved. Given this, in a wide potential window of 0–4.5 V, the MoS2@C//AC device has the highest energy density (189.68 Wh kg−1), the maximum power density (11.25 kW kg−1), subordinate self-discharge rate and long lifespan. Therefore, this research work provides some important ideas and insights for the rational design of MoS2-based high-performance LICs anode materials.