Hydrogel-Derived Nanoporous Sn-In-Ni Ternary Alloy Network for High-Performance Lithium-Storage

Nanoporous multinary alloy networks containing multiple functional components, i. e. active Li-alloying main-group metals and inactive transition-metals, possess unique structural and compositional features toward lithium storage, and are thus anticipated to manifest desirable anodic performance in advanced lithium-ion batteries (LIBs). Herein, a general and scalable one-pot hydrogel-derived route has been developed for the construction of nanoporous multinary alloy networks via facile coordination-reduction processes using novel cyano-bridged coordination polymer hydrogels (cyanogels) as precursors. The formation of nanoporous Sn-In-Ni ternary alloy network has been illustrated as an example by using a Sn(IV)-In(III)-Ni(II)-Co(III) quaternary metallic cyanogel as a precursor. Meanwhile, nanoporous Sn-Ni binary alloy and metallic In networks have also been synthesized through coordination-reduction routes using Sn(IV)-Ni(II) and In(III)-Co(III) cyanogels as precursors, respectively. Moreover, the anodic performance of the nanoporous Sn-In-Ni ternary alloy network has been examined as a proof-of-concept demonstration of its structural and compositional superiorities toward lithium storage. Compared with separate Sn-Ni and In networks, the Sn-In-Ni ternary alloy network manifests markedly enhanced lithium-storage performance in terms of reversible capacities, cycling stability, and so forth, making it an ideal anodic candidate for advanced LIBs with long cycle life and high energy/power densities. Moreover, the proposed hydrogel-derived coordination-reduction strategy would open up new opportunities for constructing nanoporous multinary alloy networks as advanced anodes for LIBs.