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

Weili An,Qiaobao Zhang,Biao Gao,Kaifu Huo,Jijiang Fu,Paul K Chu,Lei Wang,Ben Xiang,Shixiong Mei

doi:10.1038/s41467-019-09510-5

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−1 at 2,100 mA g−1 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−2. The full cell with the prelithiated silicon anode and Li(Ni1/3Co1/3Mn1/3)O2 cathode boasts a high energy density of 502 Wh Kg−1 and 84% capacity retention after 400 cycles. This work provides insights into the rational design of alloy anodes for high-energy batteries.

Highlights

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
The large capacity decay during the first 20 cycles is attributed to the increased current density from 0.05 to 0.5 C and continuous formation of solid-electrolyte interface (SEI) due to the slow penetration of the viscous organic electrolyte into the continuous porous structure in ant-nest-like microscale porous Si (AMPSi)@C as a result of strong capillary effects, volume expansion of Si, and low crystalline carbon coating
After removing Mg3N2 in an acidic solution, the bulk Si microparticles are produced, which consist of a bicontinuous porous network and crystalline Si nanoligaments resembling ant nests

Summary

Introduction

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.

Results

Conclusion