Aqueous zinc ion batteries based on sodium vanadate electrode materials with long lifespan and high energy density

We have prepared Na 7 V 7.6 O 20 ·4H 2 O (NVO) nanobelts by a facile hydrothermal route. The assembled NVO/Zn batteries deliver a capacity of 309.4 mA h g −1 at 0.3 A g −1 and maintain excellent cycling stability after 10 000 cycles at 10 A g −1 .