Improvement of Energy Capacity with Vitamin C Treated Dual-Layered Graphene-Sulfur Cathodes in Lithium-Sulfur Batteries.
A graphene-based cathode design for lithium-sulfur batteries (LSB) that shows excellent electrochemical performance is proposed. The dual-layered cathode is composed of a sulfur active layer and a polysulfide absorption layer, and both layers are based on vitamin C treated graphene oxide at various degrees of reduction. By controlling the degree of reduction of graphene, the dual-layered cathode can increase sulfur utilization dramatically owing to the uniform formation of nanosized sulfur particles, the chemical bonding of dissolved polysulfides on the oxygen-rich sulfur active layer, and the physisorption of free polysulfides on the absorption layer. This approach enables a LSB with a high specific capacity of over 600 mAh gsulfur (-1) after 100 cycles even under a high current rate of 1C (1675 mA gsulfur (-1) ). An intriguing aspect of our work is the synthesis of a high-performance dual-layered cathode by a green chemistry method, which could be a promising approach to LSBs with high energy and power densities.
Electrochemical Reaction and Technology Laboratory (ERTL), School of Environmental Science and Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju 500-712 (South Korea).
Jin Won
JW
Kim
Electrochemical Reaction and Technology Laboratory (ERTL), School of Environmental Science and Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju 500-712 (South Korea).
Joey D
JD
Ocon
Gwangju Research Center, Korea Institute of Industrial Technology (KITECH), Gwangju 506-824 (South Korea).
Ho-Sung
HS
Kim
Electrochemical Reaction and Technology Laboratory (ERTL), School of Environmental Science and Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju 500-712 (South Korea). jaeyoung@gist.ac.kr.|Ertl Center for Electrochemistry and Catalysis, Research Institute for Solar and Sustainable Energies, Gwangju Institute of Science and Technology (GIST), Gwangju 500-712 (South Korea). jaeyoung@gist.ac.kr.
Jaeyoung
J
Lee
D001205:Ascorbic Acid / Q000737:chemistry*; D011211:Electric Power Supplies; D004566:Electrodes; D006108:Graphite / Q000737:chemistry*; D008094:Lithium / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D010087:Oxides / Q000737:chemistry; D056951:Photoelectron Spectroscopy; D013455:Sulfur / Q000737:chemistry*; D014961:X-Ray Diffraction
D010087:Oxides; D013455:Sulfur; D006108:Graphite; D008094:Lithium; D001205:Ascorbic Acid
graphene; lithium; nanoparticles; reduction; sulfur