Rational design of copper phosphate based polyanionic framework for high performance supercapacitor

• Published in: Electrochimica acta 2024-09, Vol.498, p.144644, Article 144644
• Main Authors: Subbiah, Mahalakshmi, Almarhoon, Zainab M., Mariappan, Annalakshmi, Venkatachalam, Sabarinathan, Pitchaimuthu, Sudhagar, Srinivasan, Nagarajan
• Format: Article
• Language: English
• Subjects: Copper phosphate; Cyclic stability; Energy storage materials; Polyanionic framework; Supercapacitor
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2024.144644

•The simple & cost effective Cu3(PO4)2 was synthesized by the facile hydrothermal technique.•Due to the inductive effect of phosphate (PO4)2− group, the Cu3(PO4)2 shows high operating discharge voltage widow of – 1.2 V.•The maximum specific capacitance of about 814 F/g was achieved due to the conversion type mechanism of copper. It also shows excelled cyclic stability of 100 % over 10,000 cycles without any structural distortion.•The fabricated symmetric device delivers remarkable power and energy density of 4.5 kW/kg and 31.5 Wh/kg, respectively.•The constructed device shows high capacitance retention 92 % without its sacrificing its columbic efficiency. The key to high-performing supercapacitors is their abundance, low cost, and ability to deliver high capacitance in a wide electrochemical window. A new class of phosphate-based polyanion material has been developed to deliver high capacitance via the effective utilization of their oxidation states. Cu3(PO4)2 was synthesized by the facile hydrothermal technique and delivers an ultra high specific capacitance of about 814 F/g with multiple discharge plateaus at a current density of 1 A/g within a voltage window ranging from 0.4 v to -1.2 V. This intriguing behavior is mainly due to the multi functional Cu while interacts with the electrolytic ions and also the inductive effect of a phosphate group (PO4)2− contributes to a high discharge voltage of -1.2 V during charging and discharging process. It shows exceptional cyclic stability of 100 % over 10,000 cycles without sacrificing its coulombic efficiency and it is pertinent the structural stability of the system. The symmetric device was fabricated and delivered power density and energy density of 4.5 kW/kg and 31.5 Wh/kg, and also maintained excellent cyclic stability at 92 % with high reversibility of charged ions. This offers new insights into the high potential of using polyanion-type compounds as high-capacity materials for advanced energy storage systems. [Display omitted]