In traditional Li‐ion batteries, the electrolyte consists of a Li‐conducting salt dissolved in organic solvents at a concentration of 1 mol L⁻¹ (1 M). In this work, we use increased LiPF₆ concentrations between 1 and 2.3 M to investigate the influence of the electrolyte salt concentration on the rate capability of ultra‐thick (49.5 mg cm⁻²) and thin (5.6 mg cm⁻²) NCM 622 electrodes, respectively. At higher electrolyte salt concentrations than 1 M, thin electrodes suffer from increased polarization, due to a higher viscosity and a reduced ionic conductivity. In contrast, by raising the salt concentration from 1 to 1.9 M the discharge capacity of ultra‐thick electrodes is increased by more than 50 % for current densities above 3 mA cm⁻², which significantly improves their rate capability. 3D microstructure resolved simulations revealed that this effect results from the mitigation of Li‐ion depletion in the electrolyte filled pore space of ultra‐thick electrodes.

中文翻译：

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电解质盐浓度对超厚NCM 622电极速率能力的影响

在传统的锂离子电池中，电解质由溶解在有机溶剂中的锂导电盐组成，浓度为 1 mol L ^-1（1 M）。在这项工作中，我们使用介于1和2.3 M之间的增加的LiPF ₆浓度来研究电解质盐浓度对超厚（49.5 mg cm ^-2）和薄（5.6 mg cm ^-2）速率能力的影响。）NCM 622电极。在高于1 M的电解质盐浓度下，由于较高的粘度和降低的离子电导率，薄电极的极化增加。相反，通过将盐浓度从1 M增加到1.9 M，对于3 mA cm ^-2以上的电流密度，超厚电极的放电容量增加了50％以上，这大大提高了其倍率能力。3D微观结构解析模拟显示，这种效应是由于减轻了超厚电极的电解质填充孔空间中的锂离子消耗所致。