Hydrothermal synthesis of caterpillar-like one-dimensional NiCO₃ nanosheet arrays and primary lithium battery...

Transition metal carbonates have shown great potential as anode materials for next-generation lithium-ion batteries (LIBs), due to their super-high capacity. However, pure-phase NiCO₃ with high electrochemical activity has not been reported to date. Herein, highly uniform caterpillar-like one-dimensional (1D) NiCO₃ nanosheet arrays have been successfully synthesized using a facile hydrothermal route and have been evaluated as an anode material for LIBs. Profiting from the unique 1D hierarchical structure and spaces between the neighboring nanosheets, the as-prepared NiCO₃ requires lower activation energy and delivers quick lithium-ion diffusion kinetics. These attributes result in a high capacity of 893 mA h g^-1 after 150 cycles and excellent rate performance, superior to those of most reported transition metal carbonates. Cyclic voltammetry, ex situ X-ray diffraction and X-ray photoelectron spectroscopy reveal the lithium storage mechanism.