Hierarchical Hollow Bimetal Oxide Microspheres Synthesized through a Recrystallization Mechanism for High‐Performance Lithium‐Ion Batteries

Abstract

Bimetal oxide with its intricate nanostructure holds great potential for high‐performance electrode materials in lithium‐ion batteries (LIBs). Herein, a facile strategy for the fabrication of hierarchical hollow Co3O4/ZnCo2O4 microspheres is developed, involving a simple solvothermal synthesis and subsequent thermal annealing in air. An aggregation‐dissolution‐in situ recrystallization structure evolution and growth mechanism is proposed. Benefiting from the unique hierarchical hollow structure with rational porosity, synergistic effect of bimetal components, and better electrical conductivity, the as‐synthesized Co3O4/ZnCo2O4 hierarchical hollow microstructure shows outstanding lithium storage properties. As a result, a superior rate capability (842 mA h g−1 at a current density of 4 A g−1) and an excellent cycle life (754 mA h g−1 after 800 cycles at a current density of 2 A g−1) are obtained. The presented strategy could be applicable to the synthesis of mixed metal oxide hierarchical hollow structures with rational porosity for high‐performance LIBs.

Recent progress in ZnCo2O4 and its composites for energy storage and conversion: a review

“…15D). Li et al 178 Another strategy to solve concerns in terms of lithium diffusion kinetics, electronic transport, volume change, and particle agglomeration is to anchor ZnCo 2 O 4 structures onto electrically conductive nanostructured carbon materials. Hence, some carbonaceous materials including carbon nanotubes (CNTs), 129,198,199 reduced graphene oxide (rGO), [187][188][189][190][191][192] polyaniline (PAN), 210 n-doped carbon layers, 208,222 carbon cloth (CC), 194,195,223 and carbon porous structures [202][203][204] were used as inert and conductive matrices in ZnCo 2 O 4 based anode materials.…”

“…Although the theoretical capacity of ZnCo 2 O 4 as an anode material is high (900 mA h g −1 ), 154 tremendous efforts have been paid, in recent years, to increasing the conductivity and overcoming the volume expansion of ZnCo 2 O 4 caused by lithium-ion insertion/extraction, which results in its fast fading of capacity. One strategy is the combination with transition metal oxides such as ZnO/ZnCo 2 O 4 /Co 3 O 4 , 180 ZnCo 2 O 4 /Co 3 O 4 , 177–179 N-ZnCo 2 O 4 /CoO, 183 ZnCo 2 O 4 @NiO, 185 Ni–NiCo 2 O 4 @ZnCo 2 O 4 , 181 and ZnCo 2 O 4 @Fe 2 O 3 –C, 182 which can alleviate the problem through the synergy effect of bimetallic oxides.…”

“…15D). Li et al 178 also prepared ZnCo 2 O 4 /Co 3 O 4 hierarchical hollow ZnCo 2 O 4 /Co 3 O 4 microspheres via solvothermal synthesis followed by thermal annealing. When used as an anode material for LIBs, this material exhibits a rate capability of 842 mA h g −1 at a current density of 4 A g −1 and a cycle life of 754 mA h g −1 after 800 cycles at a current density of 2 A g −1 .…”

“…The as-prepared composite exhibits an enhanced lithium storage property of 1350.0 mA h g -1 at 0.3 A g -1 and cycling performance of 64% over 105 cycles at 0.3 A g -1 (Figure 15D). Li et al 171 also prepared ZnCo2O4/Co3O4 hierarchical hollow ZnCo2O4/Co3O4 microspheres via solvothermal synthesis followed by thermal annealing. When used as anode material for…”