According to research published in Small recently, a team led by Prof. HU Linhua from Hefei Institutes of Physical Science (HFIPS), Chinese Academy of Science (CAS) found that the electrochemical properties of NH 4 V 4 O 10 can be successfully enhanced by introducing oxygen vacancies.
"The introduction of oxygen vacancy accelerates the ion and charge transfer kinetics, reduces the diffusion barrier of zinc ions, and establishes a stable crystal structure during zinc ion (de-intercalation)." said LI Zhaoqian, member of the team.
Aqueous zinc ion batteries (AZIBs) have attracted significant attention among energy storage devices. Vanadium-based compounds have been identified as promising cathode materials for aqueous zinc ion batteries due to the high specific capacity. However, the low intrinsic conductivity and sluggish Zn 2+ diffusion kinetics seriously impede their further practical application.
In this study, researchers develop a facile hydrothermal approach to introduce oxygen vacancies into NH 4 V 4 O 10 nanobelts (denoted as VO-NVO) as a cathode material for high-performance AZIBs.
Generating oxygen vacancies into NVO lattice can accelerates the ion and charge transfer kinetics, reduces the diffusion barrier of zinc ions, and establishes a stable crystal structure during zinc ion (de-intercalation). This defect engineering also facilitates the enhancement of the surface capacitive contribution of NVO due to the higher electrochemical surface reactivity and lower required number of formation electrons. As a result, the obtained VO-NVO cathode delivers a remarkable capacity of 498.6 mAh g -1 at 200 mA g -1 , exceptional rate capability of 295.6 mAh g -1 at 10 A g -1 and ultra long cycling stability with a capacity retention of 95.1% after 4000 cycles at 5 A g -1 .
This method of introducing oxygen vacancies provides an idea for solving the problem of AZIB high-performance cathodes, according to the team.
Small
Oxygen Vacancies Boosts Performance of Aqueous Zinc Ion Batteries, Study finds
24-Dec-2023