以椰壳为原料制备硬碳材料，用于钠离子电池

摘要：生物质衍生硬碳（HC）因其广泛的可用性、低成本和强可调性而备受关注。然而，其相对较低的可逆容量和初始库仑效率（ICE）阻碍了其商业化。本文，浙江大学王树荣教授团队、上海电气集团股份有限公司Bin Ru等《Electrochimica Acta》期刊发表名为

1成果简介

生物质衍生硬碳（HC）因其广泛的可用性、低成本和强可调性而备受关注。然而，其相对较低的可逆容量和初始库仑效率（ICE）阻碍了其商业化。本文，浙江大学王树荣教授团队、上海电气集团股份有限公司Bin Ru等《Electrochimica Acta》期刊发表名为“Effect of pore structure regulation in coconut shell-derived hard carbon on sodium storage capacity”的论文，研究提出以一种以椰壳为原料制备硬碳（CSHC）作为钠离子电池负极材料的制备策略。通过化学活化结合高温碳化，CSHC中形成了独特的孔隙结构。通过优化碱浸渍浓度和碳化温度，优化后的CSHC-15-1400实现了372 mAh g-1的高比容量和91.6%的ICE。

研究结果表明，合理设计的孔隙结构和适宜的石墨层间距显著提升了HC材料的钠离子储存容量和循环稳定性。此外，循环伏安法（CV）动力学分析和恒电流间歇滴定技术（GITT）测试揭示了CSHC-15-1400在斜率区和平稳区独特的钠储存机制，为进一步提升HC材料性能提供了理论依据。本研究为生物质衍生硬碳在能源存储应用中的商业化提供了新思路。

2图文导读

图 1. (a) Schematic illustration of the synthesis of coconut shell-derived HC; (b) SEM image of CSHC-15-1400; (c) HRTEM image of CSHC-10-1300; (d) HRTEM image of CSHC-15-1300; (e) HRTEM image of CSHC-20-1300; (f) HRTEM image of CSHC-15-1400; (g) HRTEM image of CSHC-15-1500.

图2. (a) XRD patterns of CSHCs; (b) Raman spectra of CSHCs; (c) N2 adsorption-desorption isotherms of CSHCs; (d) XPS survey spectrum of CSHC-15-1400; (e) High-resolution C1s spectrum of CSHC-15-1400; (f) High-resolution O1s spectrum of CSHC-15-1400.

图3. (a) SAXS patterns of CSHCs; (b) SAXS fitting curve of CSHC-15-1400; (c) True density and closed pore volume of CSHCs; (d) Schematic illustration of closed pore evolution.

图4. (a-e) The first three GCD curves of CSHCs at 0.1 C; (f) Proportion of slope and plateau capacities; (g) Rate performance tests of CSHCs; (h) Long cycling tests of CSHCs at 0.5 C for 100 cycles; (i) Long cycling tests of CSHCs at 10 C for 3000 cycles.

图5. (a) CV curve at a scan rate of 0.2 mV s⁻¹, (b) CV curves at different scan rates, (c) Pseudocapacitive contribution at 1.0 mV s⁻¹ of CSHC-15-1400; (d) log(i) vs. log(v) at peak A; (e) log(i) vs. log(v) at peak B; (f) Pseudocapacitive contributions at different scan rates.

图6. (a) GITT curves of CSHCs; (b) Ionic diffusion coefficient during the desodiation process, (c) Ionic diffusion coefficient during the sodiation process of CSHC-15-1400; (d) Schematic illustration of the "adsorption-intercalation/filling" mechanism.

图7. (a) Schematic diagram of the full cell structure, (b) GCD curves at different current densities, (c) First three GCD curves at 0.1 C, (d) Cycling performance at 1 C of CSHC-15-1400//NVP with CSHC-15-1400 as the anode and NVP as the cathode.

3小结

本研究表明，当CSHC-15-1400用作钠离子电池的阳极材料时，其在0.1 C充放电速率下展现出令人印象深刻的比容量（372 mAh g-1），并具有卓越的循环稳定性。通过对化学活化及碳化温度工艺的精细优化，该材料已实现最优孔结构与层间距，从而显著提升了钠离子储存效率。在电化学性能测试中，CSHC-15-1400在0.1C至2C的电流密度范围内保持出色的倍率性能。构建的CSHC-15-1400//NVP全电池系统展现出高达280 mAh g-1的可逆比容量及219.3 Wh kg-1的能量密度。本研究提出的“吸附-插层/填充”钠储存机制为进一步提升HC材料在锂离子电池中的应用奠定了坚实的理论基础，并拓展了生物质衍生HC材料在能源存储技术中的应用前景。

文献：https://doi.org/10.1016/j.electacta.2025.147046