Scalable synthesis of ant-nest-like bulk porous silicon for high-performance lithium-ion battery anodes.

An, Weili; Gao, Biao; Mei, Shixiong; Xiang, Ben; Fu, Jijiang; Wang, Lei; Zhang, Qiaobao; Chu, Paul K et al. · Nat Commun · 2019

basic_science · Level V

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Abstract

Although silicon is a promising anode material for lithium-ion batteries, scalable synthesis of silicon anodes with good cyclability and low electrode swelling remains a significant challenge. Herein, we report a scalable top-down technique to produce ant-nest-like porous silicon from magnesium-silicon alloy. The ant-nest-like porous silicon comprising three-dimensional interconnected silicon nanoligaments and bicontinuous nanopores can prevent pulverization and accommodate volume expansion during cycling resulting in negligible particle-level outward expansion. The carbon-coated porous silicon anode delivers a high capacity of 1,271 mAh g<sup>-1</sup> at 2,100 mA g<sup>-1</sup> with 90% capacity retention after 1,000 cycles and has a low electrode swelling of 17.8% at a high areal capacity of 5.1 mAh cm<sup>-2</sup>. The full cell with the prelithiated silicon anode and Li(Ni<sub>1/3</sub>Co<sub>1/3</sub>Mn<sub>1/3</sub>)O<sub>2</sub> cathode boasts a high energy density of 502 Wh Kg<sup>-1</sup> and 84% capacity retention after 400 cycles. This work provides insights into the rational design of alloy anodes for high-energy batteries.