Sodium‐ion batteries are expected to be an alternative to lithium‐ion batteries because of the inexpensive raw materials. However, the anode materials still face problems of low capacity and initial coulomb efficiency, even for hard carbons that are expected to have commercial applications. Herein, a resin nanosphere derived from lignin through double solvent evaporation and resinification is reported. Benefiting from the phenol–formaldehyde condensation to form linear polymers, the samples possess a large microcrystalline size, moderate interlayer distance, and defect sites in the turbostratic structure, which enhance the sodium‐storage capacity. The carbonized lignin‐based resin spheres (CLRSs) exhibit promising electrochemical performance with a comparable reversible capacity of 347 mAh g⁻¹ and high initial columbic efficiency (ICE) of 74%. Furthermore, the sodium‐storage mechanism for the obtained samples is also investigated by analyzing the relationship between the structure optimization and electrochemical performance.

中文翻译：

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通过树脂化来优化高性能钠离子电池阳极的木质素基纳米球的微晶结构

由于原料便宜，因此钠离子电池有望替代锂离子电池。然而，阳极材料仍然面临低容量和初始库伦效率的问题，即使对于预期具有商业应用的硬碳也是如此。在本文中，报道了通过两次溶剂蒸发和树脂化衍生自木质素的树脂纳米球。得益于苯酚-甲醛缩合形成线型聚合物，样品具有较大的微晶尺寸，适中的层间距离以及涡轮层结构中的缺陷位点，从而提高了钠储存能力。碳化的木质素基树脂球（CLRS）表现出令人鼓舞的电化学性能，可逆容量为347 mAh g ^-1并且初始初始库仑效率（ICE）为74％。此外，通过分析结构优化与电化学性能之间的关系，还研究了所得样品的钠存储机理。