The composition of lithium-ion battery positive electrodes, incorporating an active material, conductive carbon additives, and a binder, fundamentally influences the electrode physical and electrochemical characteristics. In this study, the properties of positive electrodes with a high amount of an active material (LiNiMnCoO 98 wt-%), were tested with different ratios of carbon nanotubes (CNTs) and carbon black (CB) additives, along with varying amounts of a PVDF binder. Consequently, the electrode rate capability improves with the increase of CNTs up to 30 wt-% in the total conductive carbon share and increasing the binder amount to 1 wt-%, attributed to the optimal balance of inactive material amount. The optimal composition is determined to be 98 wt-% NMC622, 1 wt-% PVDF, and 1 wt-% total conductive carbons, out of which CNT shares accounting for 30 wt-%. Furthermore, this study continues by comparing the optimal composition with the reference electrode (CNT-free) to assess the impact of CNTs on electrochemical performance. With CNTs present, the electrode attains higher energy density and specific capacity owing to uniform conductive network. Operando XRD and dilatometry experiments also reveal that CNTs reduce irreversible height change during cycling and minimize anisotropic lattice changes, thus enhancing capacity retention.

中文翻译：

---

具有高活性材料含量的优化 NMC622 电极：综合研究


锂离子电池正极的组成包括活性材料、导电碳添加剂和粘合剂，从根本上影响电极的物理和电化学特性。在本研究中，使用不同比例的碳纳米管 (CNT) 和炭黑 (CB) 添加剂以及不同量的活性材料 (LiNiMnCoO 98 wt-%) 测试了正极的性能。聚偏氟乙烯粘合剂。因此，随着碳纳米管在总导电碳份额中增加至 30 重量%，并将粘合剂量增加至 1 重量%，电极倍率性能得到改善，这归因于非活性材料量的最佳平衡。确定最佳组成为 98 wt-% NMC622、1 wt-% PVDF 和 1 wt-% 总导电碳，其中 CNT 占 30 wt-%。此外，本研究继续将最佳成分与参比电极（不含碳纳米管）进行比较，以评估碳纳米管对电化学性能的影响。由于存在碳纳米管，电极由于均匀的导电网络而获得更高的能量密度和比容量。操作 XRD 和膨胀测量实验还表明，碳纳米管减少了循环过程中不可逆的高度变化，并最大限度地减少了各向异性晶格变化，从而提高了容量保持率。