Department of Materials Science and Engineering, Yonsei University, 50 Yonsei-ro Seodaemun-gu, Seoul 120-749, Republic of Korea.
ACS Appl Mater Interfaces. 2012 Oct 24;4(10):5408-15. doi: 10.1021/am301328u. Epub 2012 Oct 5.
The SnO(2) anode is a promising anode for next-generation Li ion batteries because of its high theoretical capacity. However, it exhibits inherent capacity fading because of the large volume change and pulverization that occur during the charge/discharge cycles. The buffer matrix, such as electrospun carbon nanofibers (CNFs), can alleviate this problem to some extent, but SnO(2) particles are thermodynamically incompatible with the carbon matrix such that large Sn agglomerates form after carbonization upon melting of the Sn. Herein, we introduce well-dispersed nanosized SnO(2) attached to CNFs for high-performance anodes developed by Ni presence. The addition of Ni increases the stability of the SnO(2) such that the morphologies of the dispersed SnO(2) phase are modified as a function of the Ni composition. The optimal adding composition is determined to be Ni:Sn = 10:90 wt % in terms of the crystallite size and the distribution uniformity. A high capacity retention of 447.6 mA h g(-1) after 100 cycles can be obtained for 10 wt % Ni-added SnO(2)-CNFs, whereas Ni-free Sn/SnO(2)-CNFs have a capacity retention of 304.6 mA h g(-1).
SnO(2) 作为下一代锂离子电池的理想阳极,具有较高的理论容量。然而,由于充放电循环过程中体积的不断变化和粉化,SnO(2) 会出现固有的容量衰减问题。缓冲基质,如静电纺丝碳纳米纤维 (CNF),在一定程度上可以缓解这个问题,但 SnO(2) 颗粒与碳基质在热力学上是不相容的,因此在 Sn 熔化碳化后会形成大的 Sn 团聚体。在此,我们引入了分散良好的纳米 SnO(2) 附着在 CNFs 上,通过 Ni 的存在开发出高性能的阳极。Ni 的加入增加了 SnO(2) 的稳定性,使得分散的 SnO(2) 相的形态随着 Ni 组成的变化而变化。根据晶粒尺寸和分布均匀性,确定最佳添加组分为 Ni:Sn = 10:90 wt%。对于添加 10wt% Ni 的 SnO(2)-CNF,在 100 次循环后可获得 447.6 mA h g(-1)的高容量保持率,而不含 Ni 的 Sn/SnO(2)-CNF 的容量保持率为 304.6 mA h g(-1)。