Erying Zhao,Zonglei Guo,Jie Liu,Qian Zhang,Ziyang Guo,Yu Yang,Hui Wang,Lei Wang
High-energy-density Li-ion batteries are urgently demanded in the development of electric vehicles and smart power grids. Owing to the high theoretical capacity, silicon (Si) has been considered as one of the most promising anode materials for next-generation Li-ion batteries. However, Si anode materials undergo huge volume change during charge and discharge processes, which severely impairs the cycle stability of Si anodes. Herein, to stabilize the Si anodes, a low-cost and eco-friendly network binder coupling hardness with softness was designed through in-situ cross-linking of guar gum (GG) and carboxylated acrylonitrile-butadiene rubber (XNBR). The rigid and high-viscosity GG functions as a skeleton to withstand the expansion of Si active materials, and the elastic XNBR can effectively buffer the residual stress. The mass ratio of GG and XNBR was systematically studied to achieve superior cycling stability of Si anodes. Especially, the Si@X4G6 electrode shows excellent cycle stability, remaining a capacity of 1929 mAh g − 1 at 1000 mA g − 1 after 100 cycles. Interestingly, such an effective strategy not only works well in Si anodes but also does well in Si/C anodes and LiFePO 4 cathodes.
Cellulose isolation, a promising way for lignocellulosic biomass utilization, is always restricted by the poor solubility of cellulose. In this paper, tetra-n-methylammonium hydroxide (TMAH) was confirmed to be capable of readily dissolving/regenerating cellulose without chemical modification at room temperature. Meanwhile, cellulose isolation from lignocellulosic biomass by initially dissolving the biomass in TMAH followed by cellulose precipitation was proposed, and the isolated substance with average cellulose purity of 92.1 ± 0.3% could be obtained throughout this process under the optimum conditions: temperature 52 °C, time 60 min, and loading ratio of TMAH/biomass ( w / w ) 7.2:1. Besides, high efficiency cellulose isolation (i.e. >70% cellulose purity) could be continuously remained during 4-round cycles by using the recycled TMAH solvent without distinct activity loss.