Improving the low-temperature capacitance of CoNiAl three-component layered double hydroxide in a redox electrolyte

The specific capacitance of CoNiAl layered double hydroxide in 6M KOH reduces sharply from room temperature to −20°C, which is effectively enhanced by adding redox pair Fe(CN)63−/Fe(CN)64− in the electrolyte. •CoNiAl layered double hydroxide is synthesized by homogeneous precipitation.•The specific capacitance reduces sharply with the decrease of temperature.•At −20°C the specific capacitance is increased by 178% in a redox electrolyte. CoNiAl three-component layered double hydroxide with a lamellar structure similar to hydrotalcite-like compounds is synthesized via homogeneous precipitation and the effect of temperature on its capacitive performances in 6M KOH is investigated. Electrochemical tests show its specific capacitance reduces sharply with the decrease of temperature from 18 to −20°C. At −20°C an increase of specific capacitance by 178% is achieved by adding redox pair Fe(CN)63−/Fe(CN)64− as the electron shuttle in the electrolyte due to their cooperation with the electrode reaction during the charge/discharge processes.