Cedarwood Bark-Derived Hard Carbon as an Anode for High-Performance Sodium-Ion Batteries

For the past few years, as an anode material for sodium-ion batteries (SIBs) with good development prospect, hard carbon material has attracted widespread attention. In this article, renewable and inexpensive cedarwood bark was used as a precursor to prepare cedarwood bark-derived carbon (CBC) materials by one-step carbonization. On characterizing the morphology and structure of the samples, the results show that the carbonization temperature has an effect on the lattice characteristics of the CBC materials. The spacing of the (002) crystal planes of the materials gradually decreases and the graphitization degree of the crystal lattice gradually increases with the increase of the temperature. The electrochemical performance of the CBC samples is also affected by the carbonization temperature. As a result, when the carbonization temperature is 800 degrees C, the material has the best electrochemical performance, the first discharge-specific capacity is as high as 547.2 mAh/g at 100 mA/g, and the reversible capacity after 150 cycles is 231.7 mAh/g. Even under current densities of 200 and 500 mA/g, the electrode can still maintain specific capacities of 193.4 and 170.1 mAh/g after 500 cycles, respectively. The layer spacing of cedarwood bark-derived carbon is larger than the distance suitable for sodium-ion insertion in theoretical calculations. Hence, the CBC materials can reversibly intercalate and deintercalate sodium ions and have good sodium storage performance.