Low-Pressure Argon/Hydrogen/Oxygen Plasma Treatment on LiMn₂O₄ Li-Ion Hybrid Supercapacitors

Abstract

LiCl + Mn(NO3)2·4H2O pastes are screen-printed on a carbon cloth substrate and then calcined at 400°C for 6 h in a tube furnace to convert them into LiMn2O4. Ar, Ar+5%H2, or Ar+5%O2 low-pressure plasma is then used to treat the LiMn2O4/carbon cloth. The treated LiMn2O4/carbon cloth is then used as the electrode for a Li-ion hybrid supercapacitors (Li-HSCs) with a three-electrode configuration in 1-M Li2SO4 liquid electrolyte. Ag/AgCl and Pt electrodes were used as reference and counter electrodes, respectively. Li-HSCs are characterized by galvanostatic charging/discharging, cyclic voltammetry, and electrochemical impedance spectroscopy. The results indicate that plasma treatment improves the Li-HSCs performance. In particular, Ar+5%O2 plasma treatment increases the areal capacity by ~24% to 23.12 µA h/cm2. It also improves the coulomb efficiency and capacity retention rate of LiMn2O4 Li-HSCs.

Ultrafast Fabrication of H2SO4, LiCl, and Li2SO4 Gel Electrolyte Supercapacitors with Reduced Graphene Oxide (rGO)-LiMnOx Electrodes Processed Using Atmospheric-Pressure Plasma Jet

“…Advantages of the work compared to reported electrolyte supercapacitors; Table S3. Comparison of electrochemical properties of rGO-LiMnOx/rGO-MnOx based supercapacitors [4,27,[53][54][55][56][57][58]…”

“…2.1. Preparation of rGO-LiCl-Mn(NO 3 ) 2 •4H 2 O Pastes RGO-LiCl-Mn(NO 3 ) 2 •4H 2 O pastes were prepared via mixing 0.05 g of rGO (thickness: <5 nm, sheet size: 0.1-5 µm; Golden Innovation Business Co., Ltd., Taipei City, Taiwan), 0.04 g of LiCl (lithium chloride, anhydrous, 99%, Alfa Aesar, Ward Hill, MA, USA), 0.3 g of Mn(NO 3 ) 2 •4H 2 O (manganese (II) nitrated tetrahydrate, 98%, Alfa Aesar, Ward Hill, USA), 3.245 g of terpineol (anhydrous, #86480, Aldrich, Munich, Germany), 1.5 g of ethanol, 1.75 g of ethyl cellulose (#46070, Sigma, Munich, Germany), and 2.25 g of ethyl cellulose (#46080, Sigma, Munich, Germany) [27]. The mixture was stirred at 850 rpm for 24 h using a magnetic stirrer and then condensed using a rotatory evaporator at 55 • C for 6 min to obtain the pastes.…”

“…Advantages of the work compared to reported electrolyte supercapacitors; Table S3. Comparison of electrochemical properties of rGO-LiMnOx/rGO-MnOx based supercapacitors [ 4 , 27 , 53 , 54 , 55 , 56 , 57 , 58 ]; Video S1: Demonstration of lighting up LED with a charged HSC.…”