Collaborative Design of Hollow Nanocubes, In Situ Cross-Linked Binder, and Amorphous Void@SiOx @C as a Three-Pronged Strategy for Ultrastable Lithium Storage.

ABSTRACT

Although silicon-based materials are ideal candidate anodes for high energy density lithium-ion batteries, the large volumetric expansion seriously damages the integrity of the electrodes and impedes commercial processes. Reasonable electrode design based on adjustable structures of silicon and strong binders prepared by a facile method is still a great challenge. Herein, a three-pronged collaborative strategy via hollow nanocubes, amorphous Void@SiOx @C, and in situ cross-linked polyacrylic acid and d-sorbitol 3D network binder (c-PAA-DS) is adopted to maintain structural/electrode integrality and stability. The all-integrated c-PAA-DS/Void@SiOx @C electrode delivers excellent mechanical property, which is attributed to ductility of the c-PAA-DS binder and high adhesion energy between Void@SiOx @C and c-PAA-DS calculated by density functional theory. Benefiting from the synergistic effect of accommodation of the hollow structure, protection of outer carbon shell, amorphous Void@SiOx @C, and strong adhesive c-PAA-DS binder, c-PAA-DS/Void@SiOx @C shows excellent electrochemical performance. Long cycling stability with a reversible capacity of 696 mAh g-1 is obtained, as well as tiny capacity decay after 500 cycles at 0.5 A g-1 and high-rate performance. The prelithiated Void@SiOx @C||LiNi0.5 Co0.2 Mn0.3 O2 (NCM523) full cell is also assembled and shows a reversible capacity of 157 mAh g-1 at 0.5 C, delivering an excellent capacity retention of 94% after 160 cycles.