Wheat Bran Derived Carbon toward Cost-Efficient and High Performance Lithium Storage
Hui Wang, Pu Zhang, Xiaolan Song, Mei Zhang, Xiaodong Kong, Shengming Jin, Xinghua Chang, Ying Zhang
Abstract
Graphite is the mainstream anode material of commercial lithium-ion batteries, while its low theoretical capacity and short supply limit its application in the ever-increasing demand for high-capacity batteries. For carbonaceous anode materials, the small surface area can endow relatively high initial Coulombic efficiency, and large mechanical strength can endow good stability during long-term cycling. In this study, sustainable wheat bran was utilized to prepare cost-efficient carbon anode via carbonization. At the reaction temperature of 800 °C, the carbonized wheat bran displayed an optimal mixed phase of ordered graphite (provided high conductivity) and amorphous carbon (provided more active sites). Due to a distinctive honeycomb-shaped hexagon structure and a small surface area of 57 m2 g–1, the as-prepared carbon material could achieve initial Coulombic efficiency up to 85%. Such an anode material revealed a superior reversible capacity of 515 mAh g–1 and corresponding retention of 92% after 1000 charge/discharge cycles. Using LiNi0.5Co0.2Mn0.3O2 as the cathode, the full cell delivered a large areal capacity of 2.66 mAh cm–2 over 200 cycles, with a high cycling stability of 82%. With such high Coulombic efficiency, areal capacity, and capacity retention, the carbonized wheat bran is on par with state-of-the-art carbonaceous anode material. This work develops a scalable and effective strategy to synthesize high-performance and low-cost carbon anode.