posted on 2021-03-10, 06:34authored byLipeng Wang, Ziyi Cao, Peiyuan Zhuang, Jiaxin Li, Hang Chu, Zhuolin Ye, Dongxiao Xu, Hong Zhang, Jianfeng Shen, Mingxin Ye
Manganese-based
compounds have emerged as attractive cathode materials
for zinc-ion batteries owing to their high operating voltage, large
specific capacity, and no pollution. However, the structural collapse
and sluggish kinetics of manganese-based compounds are major obstacles
that hinder their practical applications. Here, a kind of novel layered
Ca2Mn3O8 with a low ion diffusion
barrier and high structural stability has been achieved through an
electrochemical charging process with in situ injecting oxygen vacancies.
This greatly increases the electrochemical active area and improves
the Zn ions diffusion coefficient by 2 orders of magnitude, which
significantly enhances the reaction kinetics, pseudocapacitance properties,
and capacity. As a result, the cathode containing oxygen vacancies
present an impressive reversible capacity of 368 mAh g–1, an unprecedented energy density of 512 Wh kg–1, and superior capacity retention of 92.3% at a high current density
of 5 A g–1 after 3000 cycles. This work unveils
an effective method for vacancy regulation of electrode materials,
paving a new way to improve the electrochemical performance of zinc-ion
batteries.