Lithium ion batteries (LIBs) using silicon as anode material are endowed with much higher energy density than state-of-the-art graphite-based LIBs. However, challenges of volume expansion and related dynamic surfaces lead to continuous (re-)formation of the solid electrolyte interphase, active lithium losses, and rapid capacity fading. Cell failure can be further accelerated when Si is paired with high-capacity, but also rather reactive Ni-rich cathodes, such as LiNi_0.8Co_0.1Mn_0.1O₂ (NCM-811). Here, the practical applicability of thermal evaporation of Li metal is evaluated as a prelithiation technique on micrometer-sized Si (µ-Si) electrodes in addressing such challenges. NCM-811 || “prelithiated µ-Si” full-cells (25% degree of prelithiation) can attain a higher initial discharge capacity of ≈192 mAh g_NCM-811⁻¹ than the cells without prelithiation with only ≈160 mAh g_NCM-811⁻¹. This study deeply discusses significant consequences of electrode capacity balancing (N:P ratio) with regard to prelithiation on the performance of full-cells. The trade-off between cell lifetime and energy density is also highlighted. It is essential to point out that the phenomena discussed here can further guide the direction of research in using the thermal evaporation of Li metal as a prelithiation technique toward its practical application on Si-based LIBs.

中文翻译：

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基于锂金属的热蒸发预锂化技术在锂离子电池硅负极上的实际应用

使用硅作为阳极材料的锂离子电池 (LIB) 比最先进的石墨基 LIB 具有更高的能量密度。然而，体积膨胀和相关动态表面的挑战导致固体电解质界面的连续（重新）形成、活性锂损失和快速容量衰减。当 Si 与高容量但活性较高的富镍正极（例如 LiNi _0.8 Co _0.1 Mn _0.1 O _{2 ）搭配使用时，电池故障会进一步加速}(NCM-811)。在这里，Li 金属热蒸发的实际适用性被评估为微米级 Si (µ-Si) 电极上的预锂化技术，以应对此类挑战。NCM-811 || “预锂化 µ-Si”全电池（25% 的预锂化程度）可以获得更高的初始放电容量 ≈192 mAh g _NCM-811 ^-1比没有预锂化的电池只有 ≈160 mAh g _NCM-811 ^-1. 本研究深入讨论了电极容量平衡（N:P 比）在预锂化方面对全电池性能的重要影响。还强调了电池寿命和能量密度之间的权衡。必须指出的是，这里讨论的现象可以进一步指导使用锂金属热蒸发作为预锂化技术的研究方向，使其在硅基锂离子电池上的实际应用。