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Improvement of Energy Capacity with Vitamin C Treated Dual‐Layered Graphene–Sulfur Cathodes in Lithium–Sulfur Batteries
Author(s) -
Kim Jin Won,
Ocon Joey D.,
Kim HoSung,
Lee Jaeyoung
Publication year - 2015
Publication title -
chemsuschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.412
H-Index - 157
eISSN - 1864-564X
pISSN - 1864-5631
DOI - 10.1002/cssc.201500111
Subject(s) - graphene , sulfur , polysulfide , cathode , materials science , electrochemistry , chemical engineering , lithium–sulfur battery , lithium (medication) , inorganic chemistry , chemistry , nanotechnology , electrode , electrolyte , metallurgy , medicine , endocrinology , engineering
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 g sulfur −1 after 100 cycles even under a high current rate of 1C (1675 mA g sulfur −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.