Ultrafast Fabrication of H<sub>2</sub>SO<sub>4</sub>, LiCl, and Li<sub>2</sub>SO<sub>4</sub> Gel Electrolyte Supercapacitors with Reduced Graphene Oxide (rGO)-LiMnO<sub>x</sub> Electrodes Processed Using Atmospheric-Pressure Plasma Jet

oleh: Pei-Ling Lan, I-Chih Ni, Chih-I Wu, Cheng-Che Hsu, I-Chun Cheng, Jian-Zhang Chen

Format: Article
Diterbitkan: MDPI AG 2023-08-01

Deskripsi

Pastes containing reduced graphene oxide (rGO) and LiCl-Mn(NO<sub>3</sub>)<sub>2</sub>·4H<sub>2</sub>O are screen-printed on a carbon cloth substrate and then calcined using a nitrogen atmospheric-pressure plasma jet (APPJ) for conversion into rGO-LiMnO<sub>x</sub> nanocomposites. The APPJ processing time is within 300 s. RGO-LiMnO<sub>x</sub> on carbon cloth is used to sandwich H<sub>2</sub>SO<sub>4</sub>, LiCl, or Li<sub>2</sub>SO<sub>4</sub> gel electrolytes to form hybrid supercapacitors (HSCs). The areal capacitance, energy density, and cycling stability of the HSCs are evaluated using electrochemical measurement. The HSC utilizing the Li<sub>2</sub>SO<sub>4</sub> gel electrolyte exhibits enhanced electrode–electrolyte interface reactions and increased effective surface area due to its high pseudocapacitance (PC) ratio and lithium ion migration rate. As a result, it demonstrates the highest areal capacitance and energy density. The coupling of charges generated by embedded lithium ions with the electric double-layer capacitance (EDLC) further contributed to the significant overall capacitance enhancement. Conversely, the HSC with the H<sub>2</sub>SO<sub>4</sub> gel electrolyte exhibits better cycling stability. Our findings shed light on the interplay between gel electrolytes and electrode materials, offering insights into the design and optimization of high-performance HSCs.