Rice Husk‐Based 3D Porous Silicon/Carbon Nanocomposites as Anode for Lithium‐Ion Batteries

Abstract

Silicon/carbon (Si/C) nanocomposites with 3D porous structure are prepared by a high‐temperature hydrothermal treatment and subsequent magnesiothermic reduction using rice husks (RHs) and NaCl as Si/C sources and potential porogens. In this strategy, interconnected and uniform nanopores are introduced into RHs under the assistance of NaCl and high pressure while the organic components are carbonized, and the intermediate products (porous SiO2/C nanocomposites) are formed. The porous structure is maintained well during the high‐temperature hydrothermal treatment. After the magnesiothermic reduction of the porous SiO2/C nanocomposites, a 3D porous Si/C nanocomposite is formed, which provides rapid transferring channels for the lithium ions and accommodates volumetric changes during electrochemical cycling, leading to an improved electrochemical performance.

Enabling the ability of Li storage at high rate as anodes by utilizing natural rice husks-based hierarchically porous SiO2/N-doped carbon composites

“…Recently, lots of experiments employed biomass as the silica source due to environmental considerations. Among the various biomass materials, rice husks (RHs) have been widely applied in the LIBs [22][23][24][25][26][27][28]. The SiO 2 exists in RHs (RH-SiO 2 ) in the form of uniform nanoscale structure and coated by organic carbon component.…”

Biomass-based materials for green lithium secondary batteries

“…In contrast to introducing extra carbon sources (e.g., dopamine), Fan et al made full use of rice husk (both Si and carbon sources) to directly obtain a 3D porous Si/carbon composite material, which facilitates the rapid transfer of lithium ions and effectively accommodates the volumetric changes during battery operation, resulting in improved electrochemical performances. 307 Considering the worldwide availability on a massive scale (∼740 million tons were produced globally in 2013) and the natural hierarchical porous structures of Si sources that facilitate the electrochemical processes in biomasses, 305 it is of great significance to develop practical procedures to derive high-performance Si-based (Si, Si/C, etc.) electrode materials from biomass for large-scale applications.…”

Silicon Anodes for High‐Performance Storage Devices: Structural Design, Material Compounding, Advances in Electrolytes and Binders

“…Rice husks, perlite, and diatomaceous earth in nature are used as self‐templates to prepare porous silicon by magnesium thermal reduction, which is used as an anode material for lithium ion batteries to improve electrochemical performance. Rice husks porous silicon anode with the reversible capacity of 345 mAh g −1 remained after 100 cycles at 50 mA g −1 . Perlite porous silicon anode delivered a high reversible capacity of 1547 mAh g −1 and excellent cycling stability (85% capacity retention after 600 discharge‐charge cycles) at a current density of 358 mA g −1 (0.1 C) as well as good rate performance (778 mAh g −1 at 2 C) and diatomaceous earth porous silicon anode capacity retention can reach 99.5% after 200 cycles, and the reversible capacity can reach 534.3 mA h g −1 even at 500 mA g −1 …”

“…In‐situ growth of carbon nanotubes in pSS pores by chemical vapor deposition (CVD). Make the material have enough interstitial space to buffer the volume expansion of silicon . The Si‐carbon nanotube (CNT) spheres obtained by rotary spray drying is showed reversible capacity of 2500 mA h g −1 with retention of 98% during 500 cycles …”