Silicon (Si) has been investigated as a promising anode material because of its high theoretical capacity (4200 mAh g^-1). However, silicon anode suffers from huge volume changes during repeated charge–discharge cycles. In this work, inspired by a remarkable success of the glutinous rice mortar in the Great Wall with ca. 2000-year history, amylopectin (AP), the key ingredient responsible for the strong bonding force, is extracted from glutinous rice and utilized as a flexible, aqueous, and resilient binder to address the most challenging drastic volume-expansion and pulverization issues of silicon anode. Additionally, the removal of toxic N-methyl-2-pyrrolidone (NMP) organic solvent makes the electrode fabrication process environmentally friendly and healthy. The as-prepared Si-AP electrode with 60 wt% of Si can uphold a high discharge capacity of 1517.9 mAh g⁻¹ at a rate of 0.1 C after 100 cycles. The cycling stability of the Si-AP has been remarkably improved in comparison with both traditional polyvinylidene fluoride (PVDF) and aqueous carboxymethylcellulose (CMC) binders. Moreover, when the content of silicon in the Si-AP electrode increases to 70 wt%, a high discharge capacity of 1463.1 mAh g⁻¹ can still be obtained after 50 cycles at 0.1° C. These preliminary results suggest that the sustainably available and environmentally benign amylopectin binders could be a promising choice for the construction of highly stable silicon anodes.

Being simple, inexpensive, scalable and environmentally friendly, microporous biomass biochars have been attracting enthusiastic attention for application in lithium-sulfur (Li-S) batteries. Herein, porous bamboo biochar is activated via a KOH/annealing process that creates a microporous structure, boosts surface area and enhances electronic conductivity. The treated sample is used to encapsulate sulfur to prepare a microporous bamboo carbon-sulfur (BC-S) nanocomposite for use as the cathode for Li-S batteries for the first time. The BC-S nanocomposite with 50 wt.% sulfur content delivers a high initial capacity of 1, 295 mA·h/g at a low discharge rate of 160 mA/g and high capacity retention of 550 mA·h/g after 150 cycles at a high discharge rate of 800 mA/g with excellent coulombic efficiency (≥95%). This suggests that the BC-S nanocomposite could be a promising cathode material for Li-S batteries.