Strain engineering of two-dimensional multilayered heterostructures for beyond-lithium-based rechargeable batteries.

Beyond-lithium-ion batteries are promising candidates for high-energy-density, low-cost and large-scale energy storage applications. However, the main challenge lies in the development of suitable electrode materials. Here, we demonstrate a new type of zero-strain cathode for reversible intercalation of beyond-Li ions (Na, K, Zn, Al) through interface strain engineering of a 2D multilayered VOPO-graphene heterostructure. In-situ characterization and theoretical calculations reveal a reversible intercalation mechanism of cations in the 2D multilayered heterostructure with a negligible volume change. When applied as cathodes in K-ion batteries, we achieve a high specific capacity of 160 mA h g and a large energy density of ~570 W h kg, presenting the best reported performance to date. Moreover, the as-prepared 2D multilayered heterostructure can also be extended as cathodes for high-performance Na, Zn, and Al-ion batteries. This work heralds a promising strategy to utilize strain engineering of 2D materials for advanced energy storage applications.