School of Metallurgy and Environment , Central South University , Changsha 410083 , China.
Advanced Manufacturing Technology Research Centre, Department of Industrial and Systems Engineering , The Hong Kong Polytechnic University , Hung Hom, Kowloon , Hong Kong, China.
Inorg Chem. 2019 Apr 1;58(7):4592-4599. doi: 10.1021/acs.inorgchem.9b00158. Epub 2019 Mar 15.
Silicon (Si) attracts extensive attention as the advanced anode material for lithium (Li)-ion batteries (LIBs) because of its ultrahigh Li storage capacity and suitable voltage plateau. Hollow porous structure and dopant-induced lattice expansion can enhance the cycling stability and transporting kinetics of Li ions. However, it is still difficult to synthesize the Si anode possessing these structures simultaneously by a facile method. Herein, the lightly boron (B)-doped spherical hollow-porous Si (B-HPSi) anode material for LIBs is synthesized by a facile magnesiothermic reduction from B-doped silica. B-HPSi exhibits local lattice expansion located on boundaries of refined subgrains. B atoms in Si contribute to the increase of the conductivity and the expansion of lattices. On the basis of the first-principles calculations, the B dopants induce the conductivity increase and local lattice expansion. As a result, B-HPSi electrodes exhibit a high specific capacity of ∼1500 mAh g at 0.84 A g and maintains 93% after 150 cycles. The reversible capacities of ∼1250, ∼1000, and ∼800 mAh g can be delivered at 2.1, 4.2, and 8.4 A g, respectively.
硅（Si）因其超高的储锂容量和适宜的电压平台，作为先进的锂离子电池（LIBs）阳极材料受到广泛关注。空心多孔结构和掺杂诱导的晶格膨胀可以提高锂离子的循环稳定性和传输动力学。然而，通过简便的方法同时合成具有这些结构的 Si 阳极仍然具有挑战性。在此，通过从掺硼二氧化硅进行简单的镁热还原，合成了用于 LIBs 的轻硼（B）掺杂的球形空心多孔硅（B-HPSi）阳极材料。B-HPSi 表现出位于精细亚晶粒边界上的局部晶格膨胀。Si 中的 B 原子有助于提高电导率和晶格的膨胀。基于第一性原理计算，B 掺杂剂诱导了电导率的增加和局部晶格的膨胀。结果，B-HPSi 电极在 0.84 A g 时表现出约 1500 mAh g 的高比容量，并且在 150 次循环后保持 93%。在 2.1、4.2 和 8.4 A g 时，可分别提供约 1250、1000 和 800 mAh g 的可逆容量。
