Electrochemical Properties Of Rice Hull Silicon As A Negative Electrode For Lithium Ion Batteries And Novel Binders For Silicon-Based Anodes

The growing demand for portable power applications is pushing traditional batteries to their theoretical limits.Silicon has the potential to be a negative electrode material to increase the capacity of lithium ion batteries.The associated volume change during lithiation/delithiation results in a decrease in capacity during cycling and a low rate of lithium diffusion within the silicon that limits high rate performance.Porous silicon can simultaneously address poor recyclability and rate capability by minimizing stress and providing a smaller silicon structure for lithium diffusion.Template-assisted synthesis and silica-to-silicon magnesium thermal reduction provide a convenient and scalable approach to porous silicon structures.The recovery of useful substances from the earth's abundant materials is of strategic importance to industrial processes.Although Si is the second most abundant element in the earth's crust,the process of forming Si nanomaterials is often complex,expensive,and energy intensive.This study shows that pure silicon nanoparticles(SiNPs)can come directly from rice husks(RHs),a rich agricultural by-product.Due to their small size(10-40 nm)and porous nature,these recovered SiNPs exhibit high performance lithium ion battery anodes with high reversible capacity(1764.7 mAh/g,which is 5 times larger than graphite anodes).Using RH as a source of raw materials,overall energy savings,green and large-scale synthesis of low-cost and functional Si nanomaterials can be achieved.Adhesives play a key role in maintaining the mechanical integrity of the electrodes in lithium ion batteries.Existing adhesives typically exhibit poor ionic conductivity at large strains,which is not suitable for high capacity silicon(Si)based negative electrodes that experience severe volume changes during cycling.Preparation of a novel composite adhesive PUA&PEDOT:PSS by annealing has the following advantages:(1)The adhesive has high Li ion diffusibility.(2)PEDOT: PSS interacts with PUA to produce a high modulus,which helps to maintain the mechanical structure of the Si negative electrode during volume shrinkage.(3)PEDOT: Strong bonding of PSS to SiOx surface improves capacity retention.The Si electrode composed of the composite binder and Si nanoparticles exhibits a high reversible capacity of more than 2194.7 mA h/g after 100 cycles of a current density of 420 mA / g,and maintains 1204 mA at a high current density of 4200 mA / g.High capacity of h/g.This innovative composite adhesive provides a new perspective on the design of multi-functional adhesives for high-power and high-capacity lithium-ion batteries.