A waste biomass derived hard carbon as a high-performance anode material for sodium-ion batteries

The utilization of renewable energies has become increasingly urgent for the sustainable development of our society. Energy storage systems are essential in order to efficiently use these energies. Sodium-ion batteries (SIBs) show bright prospect in the application for energy storage markets due to the potential low cost originating from unlimited sources and wide distribution of Na. However, the anode remains a great challenge in the industrialization of SIBs. Hard carbon holds the most promising future among all reported anodes; however, there are still two main shortcomings such as high cost and low initial coulombic efficiency, which limit its application. Here, we report a hard carbon material derived from an abundant and abandoned biomass of corn cobs (HCC) using a simple carbonization method. The HCC shows excellent sodium storage performance with a reversible capacity of ca. 300mA h g(-1), a high initial coulombic efficiency of 86% and good cycling stability. A prototype sodium-ion battery was prepared to prove the application prospect using HCC1300 as the anode and Na-0.9[Cu0.22Fe0.30Mn0.48]O-2 as the cathode, exhibiting a high energy density of 207 W h kg(-1) and a long cycle life. These excellent properties demonstrate that HCC is a potential candidate as an anode material for sodium-ion battery application.