Lou Fengliu, Zhou Haitao, Tran Trung Dung, Melandsø Buan Marthe Emelie, Vullum-Bruer Fride, Rønning Magnus, Walmsley John Charles, Chen De
Department of Chemical Engineering, Norwegian University of Science and Technology, Sem Saelands vei 4, 7491 Trondheim (Norway), Fax: (+47)73595047 http://www.nt.ntnu.no/users/chen/index.htm.
ChemSusChem. 2014 May;7(5):1335-46. doi: 10.1002/cssc.201300461. Epub 2014 Feb 27.
Coaxial carbon/metal oxide/aligned carbon nanotube (ACNT) arrays over stainless-steel foil are reported as high-performance binder-free anodes for lithium ion batteries. The coaxial arrays were prepared by growth of ACNTs over stainless-steel foil followed by coating with metal oxide and carbon. The carbon/manganese oxide/ACNT arrays can deliver an initial capacity of 738 mAh g(-1) with 99.9 % capacity retention up to 100 cycles and a capacity of 374 mAh g(-1) at a high current density of 6000 mA g(-1). The external carbon layer was recognized as a key component for high performance, and the mechanism of performance enhancement was investigated by electrochemical impedance spectroscopy, electron microscopy, and X-ray diffraction analysis. The layer increases rate capability by enhancing electrical conductivity and maintaining a low mass-transfer resistance and also improves cyclic stability by avoiding aggregation of metal-oxide particles and stabilizing the solid electrolyte interface. The resultant principle of rational electrode design was applied to an iron oxide-based system, and similar improvements were found. These coaxial nanotube arrays present a promising strategy for the rational design of high-performance binder-free anodes for lithium ion batteries.
据报道,不锈钢箔上的同轴碳/金属氧化物/取向碳纳米管(ACNT)阵列是用于锂离子电池的高性能无粘结剂阳极。通过在不锈钢箔上生长ACNT,然后涂覆金属氧化物和碳来制备同轴阵列。碳/氧化锰/ACNT阵列在高达100次循环时可提供738 mAh g⁻¹的初始容量,容量保持率为99.9%,在6000 mA g⁻¹的高电流密度下容量为374 mAh g⁻¹。外部碳层被认为是高性能的关键组成部分,并通过电化学阻抗谱、电子显微镜和X射线衍射分析研究了性能增强的机制。该层通过提高电导率和保持低传质电阻来提高倍率性能,还通过避免金属氧化物颗粒的聚集和稳定固体电解质界面来提高循环稳定性。合理电极设计的所得原理应用于基于氧化铁的体系,并发现了类似的改进。这些同轴纳米管阵列提出了一种用于合理设计锂离子电池高性能无粘结剂阳极的有前景的策略。