Zhang Yaling, Chang Shulong, Zhang Ding, Zhang Sen, Han Lei, Ye Li, Pang Rui, Shang Yuanyuan, Cao Anyuan
School of Physics and Microelectronics, and Key Laboratory of Material Physics, Zhengzhou University, Zhengzhou, Henan 450001, People's Republic of China.
Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871, People's Republic of China.
Nanotechnology. 2021 Apr 26;32(28). doi: 10.1088/1361-6528/abf194.
The transition metal sulfides/oxides have been considered as promising anode materials for lithium ion batteries due to their high theoretical capacities but have suffered limits from the unsatisfactory electronic conductivity and limited lifespan. Here, FeS micro-flowers are synthesized by hydrothermal treatment and are wared and grafted into layer-by-layer carbon nanotubes (CNT). Subsequently, FeS@FeO/CNT composite films are obtained by annealing, during which the FeS micro-flowers are partially oxidized to core-shell FeS@FeOmicro-flowers. The FeS@FeO/CNT composite electrodes exhibited high reversible capacity of 1722.4 mAh g(at a current density of 0.2 A gafter 100 cycles) and excellent cycling stability (545.1 mAh gat a current density of 2 A gafter 600 cycles) as self-supporting anodes. The prominent electrochemical performances are attributed to the unique reciprocal overlap architecture. This structure serves as a cushion to buffer large volume expansion during discharge/charge cycles, and ameliorates electrical conductivity. Due to their good specific capacity and cycle stability, these FeS@FeO/CNT films have high potential application value to be used as high-performance anodes for lithium-ion, lithium sulfur and flexible packaging batteries.
过渡金属硫化物/氧化物因其高理论容量而被认为是锂离子电池有前景的负极材料，但由于电子导率不理想和寿命有限而受到限制。在此，通过水热法合成了FeS微花，并将其包裹并逐层嫁接到碳纳米管（CNT）上。随后，通过退火获得FeS@FeO/CNT复合薄膜，在此过程中，FeS微花部分被氧化为核壳结构的FeS@FeO微花。FeS@FeO/CNT复合电极作为自支撑负极，在100次循环后（电流密度为0.2 A g时）表现出1722.4 mAh g的高可逆容量，在600次循环后（电流密度为2 A g时）表现出优异的循环稳定性（545.1 mAh g）。突出的电化学性能归因于独特的相互重叠结构。这种结构起到缓冲作用，以缓冲充放电循环过程中的大体积膨胀，并改善电导率。由于其良好的比容量和循环稳定性，这些FeS@FeO/CNT薄膜作为锂离子、锂硫和柔性封装电池的高性能负极具有很高的潜在应用价值。
