Pyrolysis of spent coffee grounds dispersed clay in N2: Production of type-II conductive ceramics with electrochemical performance.

Pyrolysis of spent coffee grounds dispersed clay in N 2 produces type-II conductive ceramics with electrochemical performance. Protective atmosphere and surface screening play important roles in converting spent coffee grounds into carbon coatings on ceramic surfaces; the former prevents oxidation of organic ingredients and confinement of pyrolysis in clay for the latter. Selective-area electrical measurements indicate resultant ceramics to be conductive and interconnected carbon coatings are further verified by SEM inspections and consistency between thermal conductivity and diffusivity. Conductive ceramics show a high usage of surface area by electric double layer charging mechanism thus giving an excellent electrochemical performance. • Spent coffee grounds dispersed clay is converted into conductive ceramics in N 2. • Protective atmosphere and surface screening are key in converting spent coffee grounds into carbon coatings on ceramics. • Interconnected carbon coatings enhance electrical conductivity and thermal conductivity. • Conductive ceramics show a high usage of surface area by electric double layer charging mechanism. • The capacitance retention is 94.53 % at 2000 charge-discharge cycles. [ABSTRACT FROM AUTHOR]