摘要
作为钠离子电池正极材料,锰基层状氧化物具有理论储钠容量高、成本低和热稳定性高等优点,但也存在因结构畸变、Na^(+)/空位有序以及过渡金属空位等带来的循环稳定性问题。研究表明,抑制过渡金属空位可有效提升锰基层状氧化物正极的电化学性能。为此,本工作对比研究了溶胶凝胶制备过程中高温淬火对Na_(0.67)Fe1/3Co_(1/3)Mn_(1/3)O_(2)(NFCMO)结构和性能的影响。结果表明,相比于未经高温淬火处理的NFCMO,高温液氮淬火合成的NFCMO-LN具有更高的比容量和倍率性能。NFCMO和NFCMO-LN在0.1C下的初始放电比容量分别为91.1 m Ah/g和129.8 m Ah/g;1C倍率下循环100周后的容量保留率分别为100%和90%。即使在10C的高倍率下,NFCMO-LN仍能提供56.2 m Ah/g的放电比容量。结构分析表明,高温液氮淬火能有效抑制过渡金属空位的产生,提升了材料的结构稳定性。研究结果为钠离子电池正极材料的结构设计和电化学性能优化提供了一种可行的技术途径。
Mn-based layered cathodes are a prominent class of cathode materials for sodium-ion batteries,characterized by high theoretical specific capacity,low cost,and high thermal stability.However,these materials are prone to structural distortions,Na+/vacancy ordering,and the formation of transition metal vacancies,which detrimentally affect cyclic stability.Previous research indicates that mitigating transition metal vacancies can effectively enhance the electrochemical performance of these cathodes.This study investigates the impact of high-temperature liquid nitrogen quenching on the structure and performance of Na_(0.67)Fe_(1/3)Co_(1/3)Mn_(1/3)O_(2)(NFCMO)and its quenched counterpart-NFCMO-LN—during the sol-gel process.NFCMO-LN exhibits improved specific capacity and rate capability compared with pristine NFCMO.Specifically,NFCMO and NFCMO-LN demonstrate initial cycle discharge capacities of 91.1 mAh/g and 129.8 mAh/g at 0.1C,respectively.Furthermore,after 100 cycles at 1C,NFCMO retains 100% of its capacity,whereas NFCMO-LN maintains 90%.Remarkably,NFCMO-LN achieves a discharge capacity of 56.2 mAh/g at a high rate of 10C.Structural analyses reveal that liquid nitrogen quenching effectively reduces transition metal vacancies and enhances structural stability,offering viable strategies for the design and optimization of cathode materials in sodium-ion batteries.
作者
谭仕荣
尹文骥
曾翠鸿
黎小琼
訚硕
纪方力
胡思江
王红强
李庆余
TAN Shirong;YIN Wenji;ZENG Cuihong;LI Xiaoqiong;QI Shuo;JI Fangli;HU Sijiang;WANG Hongqiang;LI Qingyu(Hunan Zhongwei New Energy Technology Co.,Ltd.,Changsha 410699,Hunan,China;Guangxi Key Laboratory of Low Carbon Energy Materials,School of Chemistry and Pharmacy,Guangxi Normal University,Guilin 541004,Guangxi,China)
出处
《储能科学与技术》
CAS
CSCD
北大核心
2024年第7期2399-2406,共8页
Energy Storage Science and Technology
基金
广西自然科学基金粤桂联合基金项目(2021GXNSFDA075012)。
关键词
钠离子电池
层状氧化物
锰酸钠
掺杂
淬火
sodium ion battery
layered oxide
sodium manganate
lattice doping
quenching
