Dealloying-induced dual-scale nanoporous indium-antimony anode for sodium/potassium ion batteries

InSb alloy is a promising candidate for sodium/potassium ion batteries (SIBs/PIBs) but challenged with achieving high performance by dramatic volumetric changes. Herein, nanoporous (np)-InSb with dual -scale phases (cubic/hexagonal (C/H)-InSb) was fabricated by chemical dealloying of ternary Mg-In-Sb precursor. Operando X-ray diffraction (XRD) and ex-situ characterizations well rationalize the dealloy-ing/alloying mechanisms and the formation of dual-scale microstructures/phases. As an anode for SIB/ PIBs, the np-InSb electrode exhibits superior reversible capacities and lifespan compared with the monometallic porous (p)-In electrode, stemming from the dealloying-induced dual-scale nanoporous architecture and alloying strategy with proper composition. The operando XRD results demonstrate that the (de)sodiated mechanism of the np-InSb electrode involves a two-step (de)alloying process, while the (de)potassiated mechanism is associated with a full electrochemically-driven amorphization upon cycling. Additionally, the gas evolution during the (dis)charge process was monitored by on-line mass spectrometry.(c) 2022 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by ELSEVIER B.V. and Science Press. All rights reserved.