Heterostructure Coupling Yolk‐Shelled Nanosphere for CoSe/C@NC@MoSe ₂ /N,P‐C Toward Efficient Sodium/Potassium Storage

ABSTRACT In this study, based on the component regulation, dual engineering of heterostructure and architecture is developed to construct a yolk‐shelled structure with a core of CoSe anchoring in carbon matrix and double shells of N‐doped carbon and MoSe ₂ in N,P‐doped carbon (CoSe/C@NC@MoSe ₂ /N,P‐C, CMSC). The yolk−shell structure with a void in the nanosphere can tolerate mechanical stress during the Na ⁺ /K ⁺ storage and shorten their diffusion path. Besides, the heterostructure between the CoSe and MoSe ₂ induces the built‐in electric field and reduces the adsorption energy of the Na ⁺ /K ⁺ . This can boost the reaction kinetics and enhance the cycling stability for sodium/potassium ion batteries (SIBs/PIBs). As an anode material, a capacity of 262.3 mAh g ⁻¹ is retained after 5000 cycles at 20.0 A g ⁻¹ for the SIBs, while it is also demonstrated to have stable capacities of 171.3 mAh g ⁻¹ under current of 5.0 A g ⁻¹ for 500 cycles for the PIBs. Moreover, in the full cells of CMSC//Na ₃ V ₂ (PO ₄ ) ₃ and CMSC//FePBA, high energy densities of 263.9 Wh kg ⁻¹ at 215.5 W kg ⁻¹ and 147.7 Wh kg ⁻¹ at 194.4 W kg ⁻¹ are produced, respectively. The superior electrochemical performance illustrates its promising application in practice for the CMSC anode in SIBs/PIBs.