Gu Zhen-Yi, Sun Zhong-Hui, Guo Jin-Zhi, Zhao Xin-Xin, Zhao Chen-De, Li Shao-Fang, Wang Xiao-Tong, Li Wen-Hao, Heng Yong-Li, Wu Xing-Long
MOE Key Laboratory for UV Light-Emitting Materials and Technology, Northeast Normal University, Changchun, Jilin 130024, P. R. China.
Center for Advanced Analytical Science, School of Chemistry and Chemical Engineering c/o School of Civil Engineering, Guangzhou University, Guangzhou, Guangdong 510006, China.
ACS Appl Mater Interfaces. 2020 Oct 21;12(42):47580-47589. doi: 10.1021/acsami.0c14294. Epub 2020 Oct 6.
Sodium-ion batteries (SIBs) are heralded as promising candidates for grid-scale energy storage systems due to their low cost and abundant sodium resources. Excellent rate capacity and outstanding cycling stability are always the goals for SIBs. Up to now, nearly all attention has been focused on the control of morphology and structure of electrode materials, but the influence of binders on their performance is neglected, especially in cathode materials. Herein, using NaV(PO)OF (NVPOF) as a cathode material, the influence of four different binders (sodium alginate, SA; carboxymethylcellulose sodium, CMC; poly(vinylidene fluoride), PVDF; and poly(acrylic latex), LA133) on its electrochemical performance is studied. As a result, when using SA as the binder, the electrochemical performance of the NVPOF electrode is improved significantly, which is mainly because of the high water solubility, rich carboxyl and hydroxyl groups, and high adhesive and cohesive properties of the SA binder, leading to the uniform distribution of active materials NVPOF and carbon black in electrodes, good integrity, low polarization, and superior kinetic properties of the NVPOF electrodes, as demonstrated by scanning electron microscopy, cyclic voltammetry, electrochemical impedance spectroscopy, and galvanostatic intermittent titration technique. More importantly, when coupled with a hard carbon anode, the fabricated sodium-ion full cells also exhibit excellent rate performance, thus providing a preview of their practical application. This work shows that the battery performance can be improved by matching suitable binder systems, which is believed to have great importance for the further optimization of the electrochemical performance of SIBs.
钠离子电池（SIBs）因其低成本和丰富的钠资源而被誉为电网规模储能系统的有前景的候选者。优异的倍率性能和出色的循环稳定性一直是钠离子电池的目标。到目前为止，几乎所有的注意力都集中在电极材料的形貌和结构控制上，但粘结剂对其性能的影响却被忽视了，尤其是在阴极材料方面。在此，以NaV(PO)OF（NVPOF）作为阴极材料，研究了四种不同的粘结剂（海藻酸钠，SA；羧甲基纤维素钠，CMC；聚偏氟乙烯，PVDF；以及聚丙烯酸乳胶，LA133）对其电化学性能的影响。结果表明，当使用SA作为粘结剂时，NVPOF电极的电化学性能显著提高，这主要是由于SA粘结剂具有高水溶性、丰富的羧基和羟基以及高粘结性和内聚性，使得活性材料NVPOF和炭黑在电极中均匀分布，完整性良好，极化低，NVPOF电极具有优异的动力学性能，扫描电子显微镜、循环伏安法、电化学阻抗谱和恒电流间歇滴定技术证明了这一点。更重要的是，当与硬碳阳极耦合时，所制备的钠离子全电池也表现出优异的倍率性能，从而为其实际应用提供了前景。这项工作表明，通过匹配合适的粘结剂体系可以提高电池性能，这对于进一步优化钠离子电池的电化学性能具有重要意义。
