Engineering Heterointerface to Synergistically Regulate Kinetics and Stress of Copper-Cobalt Selenide toward Reversible Magnesium/Lithium Hybrid Batteries.

Wang, Wenlong; Tian, Miao; Wang, Zhitao; Ma, Heping; Du, Yibo; Si, Wenhui; Zhang, Wenming; Yang, Hui Ying et al. · Nano Lett · 2024

basic_science · Level V

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Abstract

Metal chalcogenide-based cathodes are crucial for the development of rechargeable magnesium batteries, yet the strong electrostatic interactions of Mg<sup>2</sup><sup>+</sup> result in slow ion transport and high polarization. The Mg<sup>2</sup><sup>+</sup>/Li<sup>+</sup> hybrid battery holds promise for enhancing the energy storage capability. Herein, we establish a system that utilizes (Co,Cu)Se<sub>2</sub>/CoSe<sub><i>x</i></sub> heterostructure grown on carbon cloth as the cathode and APC-LiCl as a dual-salt electrolyte to achieve high reversible capacity, enhanced cyclic stability, and impressive rate performance. First-principles calculations and kinetic analyses are employed to uncover that constructing the heterointerface stimulates the formation of an intrinsic electric field and high-density electron flows, thereby accelerating charge transfer and ion diffusion processes. Finite element simulations further demonstrate that the heterostructure effectively alleviates stresses associated with magnesiation/lithiation to enhance the structural integrity of the material. Moreover, the multistep reaction unveils a stepwise structural transformation pathway. This study initiates a new chapter in designing heterointerface strategies for advanced energy storage devices.