Multilevel Heterostructure of MoS₂/GDYO for Lithium-Ion Batteries

Layered guest carbon materials could induce interlayer engineering, especially in regulating the interlayer structure and electronic properties of the hosts, leading to high performance in Li-ion batteries (LIBs). Here, crystalline graphdiyne oxide (GDYO) is successfully inserted into MoS2 gallery via electrostatic self-assembly. Experimental and theoretical data show that GDYO-embedding induces interlayer engineering of MoS2 causing (i) enlarged MoS2 interlayer distance (supplying additional Li-ion diffusion channels and storage sites and mitigating volume change), (ii) creating interfacial electric fields (significantly improving Li-ion transport kinetics), (iii) limiting the electrochemical products of Mo and soluble lithium polysulfide (MoS2 structure regeneration), and (iv) regulation of the interfacial current density distribution during the electrochemical reaction (uniform Li plating). Moreover, through systematic ex situ and in situ investigations, the triple-mechanism of Li-ion storage is thoroughly elucidated in the heterostructure, emphasizing the positive effects of GDYO intercalation on the interfacial and interlayer storage as well as the phase conversion processes. Such a MoS2/GDYO anode exhibits high reversible capacity (approximate to 652.6 mAh g(-1) at 2.0 A g(-1)) and superior cyclic stability of 655.1 mAh g(-1) after 1000 cycles. GDYO-induced interlayer engineering based on host-guest chemistry can provide new ideas for designing effective heterostructures for high-performance energy storage and conversion systems.