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Facile Synthesis of 3D MnO 2 –Graphene and Carbon Nanotube–Graphene Composite Networks for High‐Performance, Flexible, All‐Solid‐State Asymmetric Supercapacitors
Author(s) -
Zhang Zheye,
Xiao Fei,
Qian Lihua,
Xiao Junwu,
Wang Shuai,
Liu Yunqi
Publication year - 2014
Publication title -
advanced energy materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.08
H-Index - 220
eISSN - 1614-6840
pISSN - 1614-6832
DOI - 10.1002/aenm.201400064
Subject(s) - graphene , materials science , supercapacitor , carbon nanotube , nanotechnology , graphene foam , composite number , electrode , electrochemistry , graphene oxide paper , composite material , chemistry
The integration of graphene nanosheets on the macroscopic level using a self‐assembly method has been recognized as one of the most effective strategies to realize the practical applications of graphene materials. Here, a facile and scalable method is developed to synthesis two types of graphene‐based networks, manganese dioxide (MnO 2 )–graphene foam and carbon nanotube (CNT)–graphene foam, by solution casting and subsequent electrochemical methods. Their practical applications in flexible all‐solid‐state asymmetric supercapacitors are explored. The proposed method facilitates the structural integration of graphene foam and the electroactive material and offers several advantages including simplicity, efficiency, low‐temperature, and low‐cost. The as‐prepared MnO 2 –graphene and CNT–graphene electrodes exhibit high specific capacitances and rate capability. By using polymer gel electrolytes, a flexible all‐solid‐state asymmetric supercapacitor was synthesized with MnO 2 –graphene foam as the positive electrode and CNT‐graphene as the negative electrode. The asymmetric supercapacitors can be cycled reversibly in a high‐voltage region of 0 to 1.8 V and exhibit high energy density, remarkable rate capability, reasonable cycling performance, and excellent flexibility.