Calcium Vanadate Micro/Nanostructures for Lithium-Ion Batteries

The ability to control the composition and structure of inorganic compounds by simple synthesis methods is essential to the design and development of electrode materials of lithium-ion batteries (LIBs). Here we report the controllable synthesis of calcium vanadate micro/nanostructures via a simple hydrothermal method. By easily adjusting the pH value of a reaction system, a Ca 10 V 6 O 25 straw-bundle-like structure, Ca 2 V 2 O 7 microplatelet, and CaV 6 O 16 ·3H 2 O sponge-like macrostructure can be selectively synthesized. The regulation mechanism of different calcium vanadate micro/nanostructures was investigated. In addition, CaV 6 O 16 ·3H 2 O and CaV 6 O 16 ·3H 2 O/GO self-standing papers were obtained by pressing the sponge-like macrostructure and vacuum filtration, respectively. The electrochemical performances of the CaV 6 O 16 ·3H 2 O and CaV 6 O 16 ·3H 2 O/GO papers as the self-standing and binder-free anodes for LIBs were investigated for the first time. The as-obtained CaV 6 O 16 ·3H 2 O/GO hybrid paper anode exhibits a high discharge capacity of 664.0 mA h g –1 after 250 cycles at 200 mA g –1 and good cycling stability, demonstrating its potential application as a self-standing anode for LIBs.