Regulation of the pore structure of carbon nanosheets based electrocatalyst for efficient polysulfides phase conversions  

作　　者：Xiaoyang Liu Jingbo Zhang Kangli Liu Shijie Zhang Rouhan Hou Xiaoyi Hu Peng Zhang Guosheng Shao 

机构地区：[1]State Center for International Cooperation on Designer Low-Carbon&Environmental Materials(CDLCEM),School of Materials Science and Engineering,Zhengzhou University,Zhengzhou 450001,China [2]Zhengzhou Materials Genome Institute(ZMGI),Xingyang 450100,China

出　　处：《Journal of Materials Science & Technology》2024年第4期37-46,共10页材料科学技术（英文版）

基　　金：supported by the National Natu-ral Science Foundation of China(Nos.U2004172,51972287);the National Natural Science Foundation of Henan Province(Nos.202300410368,222301420039);the Foundation for University Key Teacher of Henan Province(No.2020GGJS009);the Science&Technology Innovation Talents in Universities of Henan Province(No.23HASTIT001);the China Postdoctoral Science Foundation(No.2021M692898).

摘　　要：The practical applications of lithium-sulfur(Li-S)batteries are hampered by the sluggish redox kinetics and polysulfides shuttle in the cyclic process,which leads to a series of problems including the loss of active materials and poor cycling efficiency.In this paper,the pore structures of carbon nanosheets based electrocatalysts were precisely controlled by regulating the content of water-soluble KCl template.The relationship between pore structures and Li-S electrochemical behavior was studied,which demonstrates a key influence of pore structure in polysulfides phase conversions.In the liquid-sloid redox reaction of polysulfides,the micropores and small mesopores(d<20 nm)exhibited little impact,while the meso-pores(d>20 nm)and macropores played a decisive role.As a typical exhibition,the nickel-embedded carbon nanosheets(Ni-CNS)with a high content of large mesopores and macropores can aid Li-S batteries in exhibiting stable cycling performance(760.1 mAh g^(-1)at 1 C after 300 cycles)and superior rate capac-ity(847.8 mAh g^(-1)at 2 C).Furthermore,even with high sulfur loading(8 mg cm^(−2))and low electrolyte(E/S is around 6μL mg^(-1)),the high area capacity of 7.7 mAh cm^(−2)at 0.05 C could be achieved.This work can provide a guideline for the design of the pore structure of carbon-based electrocatalysts toward high-efficiency sulfur species redox reactions,and afford a general,controllable,and simple approach to constructing high performance Li-S batteries.

关 键 词：Hierarchical porous carbon network ELECTROCATALYST Molten salt templating method Modified separators Li-S batteries 

分 类 号：TM912[电气工程—电力电子与电力传动] O643.36[理学—物理化学]