摘要
锂硫(Li-S)电池是一种新型二次电池,具有极高的理论比能量(2600 Wh/kg),被认为是最具前景的下一代储能电池。锂硫电池正极使用硫作为活性材料,比容量高达1675 mAh/g,是目前商业化锂离子电池正极材料磷酸铁锂(170 mAh/g)和钴酸锂(274 mAh/g)的3至5倍。此外,硫是地球上储量最丰富的元素之一,且成本低廉,环保无毒。然而,锂硫电池的商业化受制于硫及其放电产物多硫化锂的电子绝缘性、可溶性多硫化物在正负极的穿梭、充放电过程中硫的体积膨胀等问题。针对硫正极材料所存在的问题,本文从储硫、固硫、限硫的三重设计出发,通过在ZIF-67模板上原位生长制备了一种NiCo-LDH/Co_(9)S_(8)中空纳米笼结构的正极材料,实现活性硫的高容量负载。电化学测试表明,NiCo-LDH/Co_(9)S_(8)与硫复合实现了79 wt%的高硫负载量,LDH/Co_(9)S_(8)异质结纳米笼结构及双功能位点,能够使S@LDH/Co_(9)S_(8)电极实现长循环寿命,在1 C电流密度下,循环充放电685次,比容量衰减率仅为0.014%,且库伦效率稳定在95%以上。
Lithium-sulfur(Li-S) battery is a new type of secondary battery with high theoretical specific energy(2600Wh/kg),which is considered to be the most prospective and ideal next-generation energy storage device.Sulfur as the cathode material with a high specific capacity of 1675 mAh/g,which is 3-5 times than LiFePO_(4)(170 mAh/g) and LiCoO_(2)(274 mAh/g).In particular,sulfur as the most abundant element on earth which is low cost,environmentally friendly and non-toxic.However,the commercialization of Li-S batteries is limited by some issues,such as the electronic insulating properties of sulfur and lithium polysulfide,the soluble polysulfide shuttle in the positive and negative electrodes,the volume expansion of sulfur during charging and discharging.To tackle the issues of sulfur cathode materials,a NiCo-LDH/Co_(9)S_(8) hollow nanocage structure cathode material was prepared by in situ growth on ZIF-67 template.A“triple design”for sulfur storing,sulfur fixing and sulfur limiting was made for the high capacity of lithium sulfur batteries.Electrochemical tests demonstrated that the NiCo-LDH/Co_(9)S_(8) with sulfur composite achieved a high sulfur loading of 79 wt%,and the LDH/Co_(9)S_(8) heterojunction nanocage structure and double functional sites were able to achieve a long cycle life for the S@LDH/Co_(9)S_(8electrode) with a specific capacity decay rate of only 0.014% per cycle after 685 cycles at 1 C,and a stable Coulomb Efficiency at 95%.
作者
卫萌
刘银
逯含情
李帅
于占军
张丽娜
WEI Meng;LIU Yin;LU Hanqing;LI Shuai;YU Zhanjun;ZHANG Lina(Zhengzhou University of Aeronautics,Zhengzhou 450046,China;Collaborative Innovation Center of Aviation Economy Development,Zhengzhou 450046,China)
出处
《郑州航空工业管理学院学报》
2024年第1期49-56,72,共9页
Journal of Zhengzhou University of Aeronautics
基金
2023年度河南省重点研发与推广专项(科技攻关)(232102241002,212102311094,222102230108)
河南省高等学校青年骨干教师资助计划项目(2019GGJS180)
河南省高等学校重点科研项目(23B140004)
大学生创新创业训练计划(202310485010)
航空科学基金(2022Z040055001)
郑州航空工业管理学院研究生教育创新计划基金项目(2023CX77)。
关键词
金属氢氧化物
硫化钴
异质结构
锂硫电池
metal hydroxide
cobalt sulfide
heterogeneous structure
lithium-sulfur battery
