Controllable vacancy strategy mediated by organic ligands of nickel fluoride alkoxides for high-performance aqueous energy storage

Vacancy engineering plays a significant role in the rational design of electrochemical energy conversion and storage. However, limited by traditional strategies, controllably introducing abundant vacancies remains challenging. Herein, a new strategy for controllable modulation of vacancy content by regulating the number of hydrogen bonds based on nickel fluoride alkoxide precursors (denoted as F-Ni-O-x-R-y) is proposed. The hydrogen bonds are formed by micro-design of the carbon chain structure to stabilize F ions on the surface during the synthesis process. Afterward, their breakage during electrochemical reconstruction processes leads to the overall release of F ions to generate vacancies. The adjustment of the carbon chain length can effectively control the number of hydrogen bonds, further microregulating the number of vacancies. The unique microstructural design yields a reconstructed nickel fluoride alkoxide (F-Ni-O-2-R-2) electrode with an ultra-high specific capacitance of 2975 F g(-1) at a current density of 1 A g(-1). This work not only provides a new strategy for the controllable modulation of vacancy engineering, but also a new perspective for the construction of novel energy storage electrodes by incorporating organic ligands into inorganic systems.

Automated summary

A new strategy for controllable modulation of vacancy content by regulating the number of hydrogen bonds is proposed in this study, enabling the controlled introduction of abundant vacancies. Hydrogen bonds are formed through micro-design of the carbon chain structure to stabilize F ions during the synthesis process, and their breakage leads to the generation of vacancies. The carbon chain length can effectively control the number of hydrogen bonds, thereby microregulating the number of vacancies. The unique microstructural design results in a reconstructed nickel fluoride alkoxide electrode with an ultra-high specific capacitance.