Co2(OH)3Cl nanoparticles as new-type electrode material with high electrochemical performance for application in supercapacitor

- Co2(OH)3Cl nanoparticles were prepared by an epoxide precipitation route.
- Co2(OH)3Cl nanoparticles presented high performance as electrode material.
- An electrochemical process of Co2(OH)3Cl → β-Co(OH)2 → CoOOH ↔ Co3O4 was proposed.

In this work, we report the preparation of Co2(OH)3Cl nanoparticles with average size of ∼20 nm and well-defined cubic shape at room temperature by an epoxide precipitation route. It was found that the as-prepared Co2(OH)3Cl nanoparticles could be used as a promising new electrode material for application in redox supercapacitors due to its high electrochemical performance. It presented superior specific capacitance of 783 F g−1 at low current density of 2.8 A g−1, while it had a high value of 604 F g−1 at high current density of 56.6 A g−1, proving its excellent high rate performance. Its 75% capacitance retention after 10,000 cycles of charge-discharge demonstrated its long-life span. According to characterization results, the possible mechanism for the electrochemical process that Co2(OH)3Cl nanoparticles underwent was proposed as a process of Co2(OH)3Cl → β-Co(OH)2 → CoOOH ↔ Co3O4.

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