Effect of Pd doping on the structural properties and supercapacitor performance of La0.8Sr0.2Cu0.7Mn0.3O3 and La0.8Sr0.2Cu0.4Mn0.6O3 as electrode materials.

• LSCM0.3, LSCM0.6, LSCMP0.3 and LSCMP0.6 were prepared for investigation as supercapacitor electrodes. • The presence of a larger amount of Mnn+ cation with high oxidation states in the B site led to an increase in surface active points and an improvement in the electrochemical performance of LSCM0.6 compared to LSCM0.3. • Obtained high capacitance of 113 F.g−1 for LSCMP0.6 at a discharge current density of 1 A g−1. • LSCMP0.6 // LSCMP0.6 as a symmetric supercapacitor achieves high energy density of 63.28 W.h.kg−1 at 1000 W.kg−1. La 0.8 Sr 0.2 Cu 0.4 Mn 0.6 O 3 (LSCM0.6) and La 0.8 Sr 0.2 Cu 0.7 Mn 0.3 O 3 (LSCM0.3) were prepared and Pd (10 % mole in B site) was partial substituted in the B site, with the aim of investigating their performance as supercapacitor electrodes. The crystal structure, morphology and electrochemical activity of them studied in details. LSCM0.3 has a cubic structure and belongs to the Pm-3 m space group. The partial substitution of Pd in B site, increased the distortion of the structure and oxygen vacancies. La 0.8 Sr 0.2 (Cu 0.4 Mn 0.6) 0.9 Pd 0.1 O 3 (LSCMP0.6) recognized to be the best sample of the synthesized. This sample showed obvious pseudo-capacitive behavior and the highest specific capacitance (113 F.g−1) at a current density of 1 A.g−1. The improved electrochemical activity of LSCMP0.6 were originated from the structural features and higher oxygen vacancy content. Extensive charge-discharge cycles performed to assess the electrochemical stability of LSCMP0.6. It was found, after 3000 charge-discharge cycles, the specific capacitance dropped to about 70 % of its initial value. [Display omitted] [ABSTRACT FROM AUTHOR]