title: Freeze-drying for sustainable synthesis of nitrogen doped porous carbon cryogel with enhanced supercapacitor and lithium ion storage performance.
abstract: A chitosan (CS) based nitrogen doped carbon cryogel with a high specific surface area (SSA) has been directly synthesized via a combined process of freeze-drying and high-temperature carbonization without adding any activation agents. The as-made carbon cryogel demonstrates an SSA up to 1025 m(2) g(-1) and a high nitrogen content of 5.98 wt%, while its counterpart derived from CS powder only shows an SSA of 26 m(2) g(-1). Freeze-drying is a determining factor for the formation of carbon cryogel with a high SSA, where the CS powder with a size of ca. 200 μm is transformed into the sheet-shaped cryogel with a thickness of 5-8 μm. The as-made carbon cryogel keeps the sheet-shaped structure and the abundant pores are formed in situ and decorated inside the sheets during carbonization. The carbon cryogel shows significantly enhanced performance as supercapacitor and lithium ion battery electrodes in terms of capacity and rate capability due to its quasi two-dimensional (2D) structure with reduced thickness. The proposed method may provide a simple approach to configure 2D biomass-derived advanced carbon materials for energy storage devices.
authors: Carbon Research Laboratory, Liaoning Key Lab for Energy Materials and Chemical Engineering, State Key Lab of Fine Chemicals, School of Chemical Engineering, Dalian University of Technology, Dalian 116024, People's Republic of China.
authors: Zheng
authors: Z
authors: Ling
authors: Chang
authors: C
authors: Yu
authors: Xiaoming
authors: X
authors: Fan
authors: Shaohong
authors: S
authors: Liu
authors: Juan
authors: J
authors: Yang
authors: Mengdi
authors: M
authors: Zhang
authors: Gang
authors: G
authors: Wang
authors: Nan
authors: N
authors: Xiao
authors: Jieshan
authors: J
authors: Qiu