Metallic lithium (Li), considered as the ultimate anode, is expected to promise high‐energy rechargeable batteries. However, owing to the continuous Li consumption during the repeated Li plating/stripping cycling, excess amount of the Li metal anode is commonly utilized in lithium‐metal batteries (LMBs), leading to reduced energy density and increased cost. Here, an all‐solid‐state lithium‐metal battery (ASSLMB) based on a garnet‐oxide solid electrolyte with an ultralow negative/positive electrode capacity ratio (N/P ratio) is reported. Compared with the counterpart using a liquid electrolyte at the same low N/P ratios, ASSLMBs show longer cycling life, which is attributed to the higher Coulombic efficiency maintained during cycling. The effect of the species of the interface layer on the cycling performance of ASSLMBs with low N/P ratio is also studied. Importantly, it is demonstrated that the ASSLMB using a limited Li metal anode paired with a LiFePO₄ cathode (5.9 N/P ratio) delivers a stable long‐term cycling performance at room temperature. Furthermore, it is revealed that enhanced specific energies for ASSLMBs with low N/P ratios can be further achieved by the use of a high‐voltage or high mass‐loading cathode. This study sheds light on the practical high‐energy all‐solid‐state batteries under the constrained condition of a limited Li metal anode.

中文翻译：

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室温下使用石榴石型电解液的锂金属阳极有限的全固态电池

金属锂（​​Li）被认为是最终的阳极，有望成为高能可充电电池的保证。但是，由于在重复的锂电镀/剥离循环过程中持续消耗锂，锂金属电池（LMB）中通常使用过量的锂金属阳极，导致能量密度降低和成本增加。在此，报道了一种基于石榴石氧化物固体电解质的全固态锂金属电池（ASSLMB），其负/正电极容量比（N / P比）超低。与使用同样低N / P比率的液体电解质的同类产品相比，ASSLMBs显示出更长的循环寿命，这归因于循环过程中保持的更高的库仑效率。还研究了界面层种类对低N / P比的ASSLMBs循环性能的影响。重要的是，已证明使用有限的锂金属阳极与LiFePO配对的ASSLMB_4个阴极（5.9 N / P的比率）在室温下可提供稳定的长期循环性能。此外，揭示了通过使用高电压或高质量负载阴极，可以进一步实现低N / P比的ASSLMBs的增强比能。这项研究揭示了在有限的锂金属阳极约束条件下实用的高能全固态电池。