Inserting Sn Nanoparticles into the Pores of TiO2−x–C Nanofibers by Lithiation
Inserting Sn Nanoparticles into the Pores of TiO2−x–C Nanofibers by Lithiation
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DOI：
10.1002/adfm.201503711
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发表时间：
2016
影响因子：
19
通讯作者：
Xiao-yan Li;Yuming Chen;Hongtao Wang;H. Yao;Haitao Huang;Y. Mai;N. Hu;Li-min Zhou
中科院分区：
文献类型：
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作者：
Xiao-yan Li;Yuming Chen;Hongtao Wang;H. Yao;Haitao Huang;Y. Mai;N. Hu;Li-min Zhou
锡作为锂离子电池（LIB）的阳极材料具有很高的理论容量，但其循环寿命受到结构退化的限制。在此，开发了一种新的方法来将Sn纳米颗粒插入到高度稳定的二氧化钛-碳（TiO 2-x-C）多孔基底的孔中，该方法可以有效地定位后形成的较小的Sn纳米颗粒，从而解决结构退化的问题，从而实现改善的阳极性能。在第一次锂化过程中，Li4.4Sn合金通过其大体积膨胀插入到TiO 2 −x-C纳米纤维中初始Sn纳米颗粒周围的孔隙中。此后，由于插入的Sn纳米颗粒和TiO 2-x-C基底之间的表面吸收，直径约为150 nm的原始Sn纳米颗粒不能通过脱锂回收，导致许多较小的Sn纳米颗粒保留在孔中。含有这些多孔TiO 2 −x-C-Sn纳米纤维的电池在0.1 A g−1下循环200次后表现出957 mAh g−1的高容量，并且可以在3 A g−1下循环超过10000次，同时保持其容量的82.3%，这是迄今为止用于LIB的Sn基阳极的最长循环寿命。这种有趣的方法可以为其他遭受显著体积膨胀的高容量阳极材料系统提供新的途径。
Tin holds promise as an anode material for lithium‐ion batteries (LIBs) because of its high theoretical capacity, but its cycle life is limited by structural degradation. Herein, a novel approach is exploited to insert Sn nanoparticles into the pores of highly stable titanium dioxide–carbon (TiO2−x–C) nanofiber substrates that can effectively localize the postformed smaller Sn nanoparticles, thereby address the problem of structural degradation, and thus achieve improved anode performance. During first lithiation, a Li4.4Sn alloy is inserted into the pores surrounding the initial Sn nanoparticles in TiO2−x–C nanofibers by its large volume expansion. Thereafter, the original Sn nanoparticle with a diameter of about 150 nm cannot be recovered by the delithiation because of the surface absorption between inserted Sn nanoparticles and the TiO2−x–C substrate, resulting in many smaller Sn nanoparticles remaining in the pores. Batteries containing these porous TiO2−x–C–Sn nanofibers exhibit a high capacity of 957 mAh g−1 after 200 cycles at 0.1 A g−1 and can cycle over 10 000 times at 3 A g−1 while retaining 82.3% of their capacity, which represents the longest cycling life of Sn‐based anodes for LIBs so far. This interesting method can provide new avenues for other high‐capacity anode material systems that suffer from significant volume expansion.