Three-dimensional porous bowl-shaped carbon cages interspersed with carbon coated Ni-Sn alloy nanoparticles as anode materials for high-performance lithium-ion batteries
Three-dimensional porous bowl-shaped carbon cages interspersed with carbon coated Ni-Sn alloy nanoparticles as anode materials for high-performance lithium-ion batteries
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三维多孔碗状碳笼散布碳包覆Ni-Sn合金纳米粒子作为高性能锂离子电池负极材料
DOI：
10.1039/c6nj02458k
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发表时间：
2017
影响因子：
3.3
通讯作者：
Zhao Naiqin
中科院分区：
文献类型：
--
作者：
Wang Zhiyuan;Wang Dan;Luo Shaohua;Bao Shuo;Liu Yanguo;Qi Xiwei;He Chunnian;Shi Chunsheng;Zhao Naiqin
锡基负极材料在锂/脱锂过程中由于体积变化引起的结构损伤，导致其循环稳定性较差，成为其实际应用的主要障碍。在本工作中，我们以自组装的氯化钠为模板，采用冷冻干燥法制备了夹杂有碳包覆镍锡合金纳米颗粒(Ni3Sn2和Ni3Sn4；10-30 nm)的三维多孔碗状碳笼，并对其进行了热处理。Ni3Sn2/C和Ni3Sn4/C作为锂离子电池负极材料均表现出优异的电化学性能。特别是，Ni3Sn4/C纳米复合材料表现出优异的倍率性能(0.1Ag−1、0.2Ag−1、0.5Ag−1、1、2和5A g−1时分别为735、661、622、577、496和377 mA h g−1)和优异的循环稳定性(第二次循环为568 mA h g−1，经200次循环后逐渐增加到732 mA h g−1)。这种优异的电化学性能归功于镍锡合金纳米颗粒和三维多孔碗状碳网络的协同作用。均匀嵌入的镍锡合金纳米颗粒能有效缓解绝对应力应变，缩短锂离子扩散路径，镍锡合金中的镍起到了缓冲作用，抑制了体积膨胀。此外，具有高导电性的三维碗状碳网络可以为体积膨胀提供充足的空间，抑制镍锡纳米颗粒的团聚，保证结构的完整性，促进锂离子的扩散和电子的传输。
The structural damage induced by huge volume change during lithiation/delithiation results in poor cycle stability of tin-based anode materials, which becomes the major obstacle to their practical application. In this work, we fabricated three-dimensional (3D) porous bowl-shaped carbon cages interspersed with carbon coated Ni–Sn alloy nanoparticles (Ni3Sn2 and Ni3Sn4; 10–30 nm) by a freeze-drying method with self-assembled NaCl as a template followed by annealing. Both Ni3Sn2/C and Ni3Sn4/C exhibit excellent electrochemical performance as anode materials for lithium-ion batteries. In particular, the Ni3Sn4/C nanocomposites exhibit superior rate capability (735, 661, 622, 577, 496, and 377 mA h g−1 at 0.1, 0.2, 0.5, 1, 2, and 5 A g−1, respectively) and excellent cycling stability (568 mA h g−1 at 0.5 A g−1 for the second cycle and gradually increased to 732 mA h g−1 after 200 cycles). The superior electrochemical performance is attributed to the synergetic effect of Ni–Sn alloy nanoparticles and 3D porous bowl-shaped carbon networks. The uniformly embedded Ni–Sn alloy nanoparticles can effectively alleviate the absolute stress/strain and shorten the Li+ diffusion path, and Ni in the Ni–Sn alloy acts as a buffer to suppress the volume expansion. Moreover, the 3D bowl-shaped carbon networks with high conductivity can provide abundant space for volume expansion, suppress the agglomeration of Ni–Sn nanoparticles, ensure the structural integrity, and facilitate lithium-ion diffusion as well as electron transportation.