A single-crystalline Co3O4 nanoparticle-assembled three-dimensional chain as an ultra-stable magnesium-ion battery cathode at different temperatures

Engineering optimal cathode materials is significant for developing stable magnesium-ion (Mg-ion) batteries. Here, we present a single-crystalline Co3O4 nanoparticle-chain three-dimensional (3D) micro/nanostructure as an Mg-ion battery cathode. The hierarchical morphology is composed of radial nanochains self-assembled by single-crystalline nanoparticles, thus significantly facilitating the transfer of electrons and ions. 3D single-crystalline Co3O4 as an Mg-ion battery cathode displays a stable capacity of 111.7 mA h g(-1) after 200 cycles with a decay rate per cycle as low as 0.037%. After four rounds of testing, the rate performance remains stable with a tiny decrease from 125.94 to 124.78 mA h g(-1). At temperatures of 45 degrees C and -5 degrees C, the cathode still displays good stability and rate-performance. Galvanostatic intermittent titration technique (GITT) results verify a low energy barrier of the Co3O4 cathode. It is expected that the single-crystalline nanoparticle-assembled 3D structure and the stable Mg-storage performance will find broad applications for developing other stable energy-storage materials and their batteries.

Automated summary

Researchers have developed an excellent cathode material for magnesium-ion (Mg-ion) batteries, which is a single-crystalline Co3O4 nanoparticle-chain three-dimensional (3D) micro/nanostructure. The hierarchical morphology of this cathode material, composed of self-assembled single-crystalline nanoparticles, greatly facilitates the transfer of electrons and ions. The material exhibits stable capacity and cycle performance, as well as good stability at both low and high temperatures.