5L-Scale Magnesio-Milling Reduction of Nanostructured SiO₂ for High Capacity Silicon Anodes in Lithium-Ion Batteries

Abstract

Nanostructured silicon (Si) is useful in many applications and has typically been synthesized by bottom-up colloid-based solution processes or top-down gas phase reactions at high temperatures. These methods, however, suffer from toxic precursors, low yields, and impractical processing conditions (i.e., high pressure). The magnesiothermic reduction of silicon oxide (SiO) has also been introduced as an alternative method. Here, we demonstrate the reduction of SiO by a simple milling process using a lab-scale planetary-ball mill and industry-scale attrition-mill. Moreover, an ignition point where the reduction begins was consistently observed for the milling processes, which could be used to accurately monitor and control the reaction. The complete conversion of rice husk SiO to high purity Si was demonstrated, taking advantage of the rice husk's uniform nanoporosity and global availability, using a 5L-scale attrition-mill. The resulting porous Si showed excellent performance as a Li-ion battery anode, retaining 82.8% of the initial capacity of 1466 mAh g after 200 cycles.

The emerging era of supramolecular polymeric binders in silicon anodes

“…Si particles can expand and contract within the pores and buffer the mechanical stress, which leads to a more stable cyclability compared to that of the non-porous counterpart. [44][45][46] This strategy is likely to be more effective for stiff/brittle binders (such as CMC) because they cannot buffer high strain caused by the massive volume change of Si.…”

SiO2/C Composite Derived from Rice Husks with Enhanced Capacity as Anodes for Lithium‐Ion Batteries

“…For the one thing, the SiO 2 particle needs to preserve moisture and nutrients inside the kernels, for another thing it can protect rice from external attack of insects and bacteria . So the RH‐SiO 2 has developed porous nanoscale particles and tightly unifies with the organic carbon through years of natural evolution,, Which is conducive to enhance the electrochemical performance of materials. Unfortunately, due to the intrinsic structure of RHs, there is the obviously inhomogeneous distribution between porous SiO 2 nanoparticles and carbon component.…”

Metallothermic Reduction of Silica Nanoparticles to Porous Silicon for Drug Delivery Using New and Existing Reductants

“…Stöber silica NPs (238±22 nm) were prepared according to a previously reported base‐catalyzed sol–gel procedure (Figure S1) . They were mixed with −325 mesh Mg powder and NaCl, which acted as a heat sink . The reaction mixture was processed in a tube furnace under an Ar atmosphere at various temperatures and for various durations.…”

“…[67] They were mixed with À325 mesh Mg powdera nd NaCl, which acted as ah eat sink. [68,69] The reactionm ixture was processed in atube furnace under an Ar atmosphere at various temperatures and for various durations. The reduced product was treated with 1.0 m aqueous HCls olution to remove un-reactedM g, MgO, and NaCl.…”