Although hard carbons holds the most promise as anodes for practical sodium-ion batteries, high cost and low initial coulomb efficiency (ICE) limit their commercial application. In the present work, we develop an efficient solvothermal stabilization method to fabricate hard carbon spheres with high carbon yield from the wheat starch precursor. As anode for sodium-ion batteries, the obtained samples deliver not only a high capacity above 300 mAh g⁻¹, but also an enhanced initial coulombic efficiency up to 90% and long cycle stability. Furthermore, when coupled with Na_0.9[Cu_0.22Fe_0.30Mn_0.48]O₂ as cathode electrode, the full cell exhibited a high ICE of 85%, an average voltage of 3.2V and excellent stability during 300 cycles charging and discharging. These desirable electrochemical performances, combined with the renewable precursor and efficient synthesis route, make the obtained hard carbon sphere a promising anode for practical material for sodium-ion batteries.

尽管硬碳作为实用钠离子电池的阳极最有希望，但高成本和低初始库仑效率（ICE）限制了其商业应用。在目前的工作中，我们开发了一种有效的溶剂热稳定化方法，可以从小麦淀粉前体中制备高碳收率的硬碳球。作为钠离子电池的阳极，获得的样品不仅具有300 mAh g ^-1以上的高容量，而且还具有高达90％的增强的初始库伦效率和较长的循环稳定性。此外，当与Na _0.9结合时[Cu _0.22 Fe _0.30 Mn _0.48 ] O ₂作为阴极，整个电池在300次充电和放电过程中具有85％的高ICE，3.2V的平均电压和出色的稳定性。这些理想的电化学性能，结合可再生的前体和有效的合成路线，使所得的硬碳球成为钠离子电池实用材料的有希望的阳极。