title: Novel hierarchically porous carbon materials obtained from natural biopolymer as host matrixes for lithium-sulfur battery applications.
abstract: Novel hierarchically porous carbon materials with very high surface areas, large pore volumes and high electron conductivities were prepared from silk cocoon by carbonization with KOH activation. The prepared novel porous carbon-encapsulated sulfur composites were fabricated by a simple melting process and used as cathodes for lithium sulfur batteries. Because of the large surface area and hierarchically porous structure of the carbon material, soluble polysulfide intermediates can be trapped within the cathode and the volume expansion can be alleviated effectively. Moreover, the electron transport properties of the carbon materials can provide an electron conductive network and promote the utilization rate of sulfur in cathode. The prepared carbon-sulfur composite exhibited a high specific capacity and excellent cycle stability. The results show a high initial discharge capacity of 1443 mAh g(-1) and retain 804 mAh g(-1) after 80 discharge/charge cycles at a rate of 0.5 C. A Coulombic efficiency retained up to 92% after 80 cycles. The prepared hierarchically porous carbon materials were proven to be an effective host matrix for sulfur encapsulation to improve the sulfur utilization rate and restrain the dissolution of polysulfides into lithium-sulfur battery electrolytes.
authors.affiliation: The Key Laboratory of Low-carbon Chemistry & Energy Conservation of Guangdong Province/State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-sen University , Guangzhou 510275, P. R. China.
authors.forename: Bin
authors.initials: B
authors.lastname: Zhang
authors.forename: Min
authors.initials: M
authors.lastname: Xiao
authors.forename: Shuanjin
authors.initials: S
authors.lastname: Wang
authors.forename: Dongmei
authors.initials: D
authors.lastname: Han
authors.forename: Shuqin
authors.initials: S
authors.lastname: Song
authors.forename: Guohua
authors.initials: G
authors.lastname: Chen
authors.forename: Yuezhong
authors.initials: Y
authors.lastname: Meng
mesh_terms: D000327:Adsorption; D000818:Animals; D001704:Biopolymers / Q000737:chemistry*; D002244:Carbon / Q000737:chemistry*; D058266:Dielectric Spectroscopy; D004553:Electric Conductivity; D011211:Electric Power Supplies; D055664:Electrochemical Techniques; D004563:Electrochemistry; D004566:Electrodes; D008094:Lithium / Q000737:chemistry*; D009584:Nitrogen / Q000737:chemistry; D010316:Particle Size; D016062:Porosity; D047011:Silk / Q000737:chemistry; D013455:Sulfur / Q000737:chemistry*; D013696:Temperature; D013818:Thermogravimetry; D014961:X-Ray Diffraction
chemical_list: D001704:Biopolymers; D047011:Silk; D013455:Sulfur; D002244:Carbon; D008094:Lithium; D009584:Nitrogen