title: High performance solid-state electric double layer capacitor from redox mediated gel polymer electrolyte and renewable tamarind fruit shell derived porous carbon.
abstract: The activated carbon was derived from tamarind fruit shell and utilized as electrodes in a solid state electrochemical double layer capacitor (SSEDLC). The fabricated SSEDLC with PVA (polyvinyl alcohol)/H2SO4 gel electrolyte delivered high specific capacitance and energy density of 412 F g(-1) and 9.166 W h kg(-1), respectively, at 1.56 A g(-1). Subsequently, Na2MoO4 (sodium molybdate) added PVA/H2SO4 gel electrolyte was also prepared and applied for SSEDLC, to improve the performance. Surprisingly, 57.2% of specific capacitance (648 F g(-1)) and of energy density (14.4 Wh kg(-1)) was increased while introducing Na2MoO4 as the redox mediator in PVA/H2SO4 gel electrolyte. This improved performance is owed to the redox reaction between Mo(VI)/Mo(V) and Mo(VI)/Mo(IV) redox couples in Na2MoO4/PVA/H2SO4 gel electrolyte. Similarly, the fabricated device shows the excellent capacitance retention of 93% for over 3000 cycles. The present work suggests that the Na2MoO4 added PVA/H2SO4 gel is a potential electrolyte to improve the performance instead of pristine PVA/H2SO4 gel electrolyte. Based on the overall performance, it is strongly believed that the combination of tamarind fruit shell derived activated carbon and Na2MoO4/PVA/H2SO4 gel electrolyte is more attractive in the near future for high performance SSEDLCs.
authors.affiliation: Solid State Ionics and Energy Devices Laboratory, Department of Physics, Bharathiar University , Coimbatore-641046, Tamil Nadu, India.
authors.forename: S T
authors.initials: ST
authors.lastname: Senthilkumar
authors.forename: R Kalai
authors.initials: RK
authors.lastname: Selvan
authors.forename: J S
authors.initials: JS
authors.lastname: Melo
authors.forename: C
authors.initials: C
authors.lastname: Sanjeeviraja
mesh_terms: D025802:Electric Capacitance; D004573:Electrolytes; D005638:Fruit / Q000737:chemistry*; D005782:Gels / Q000737:chemistry; D037742:Nanotubes, Carbon / Q000737:chemistry*; D010084:Oxidation-Reduction; D011108:Polymers / Q000737:chemistry; D016062:Porosity; D013499:Surface Properties; D029861:Tamarindus / Q000737:chemistry*
chemical_list: D004573:Electrolytes; D005782:Gels; D037742:Nanotubes, Carbon; D011108:Polymers