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High-power solid-state batteries enabled by preferred directional lithium growth mechanism

Journal
ACS Energy Letters
Date
2022.11.16
Abstract

Solid electrolytes are revolutionizing the field of lithium-metal batteries; however, their practical implementation has been impeded by the interfacial instability between lithium metal electrodes and solid electrolytes. While various interlayers have been suggested to address this issue in recent years, the long-term stability with the repeated lithium deposition/stripping has been challenging to attain. Herein, a new interlayer design strategy is proposed, which employs (i) crystalline-direction-controlled carbon material, which provides isotropic lithium transports, with (ii) pre-lithium deposits that guides the lithium nucleation direction toward the current collector. This combination ensures that the morphology of the interlayer is mechanically robust while regulating the preferred lithium growth underneath the interlayer without disrupting the initial interlayer/electrolyte interface, thereby remarkably enhancing the durability of the interface. We illustrate how these material/geometric optimizations are conducted from the thermodynamic considerations, and its applicability is demonstrated for the garnet-type Li7-xLa3-aZr2-bO12 (LLZO) solid electrolytes paired with the high-nickel layered cathode material (LiNi0.8Co0.1Al0.1). It is shown that a lithium-metal cell with the optimized amorphous carbon interlayer with pre-lithium deposits exhibits outstanding room-temperature cycling performance (99. 6 % capacity retention after 250 cycles), delivering 4.0 mAh cm-2 at 2.5 mA cm-2 without significant degradation of the capacity. The successful long-term operation of the solid-state cell at 2.5 mA cm-2 at room temperature (~ a cumulative deliverable capacity of over 1,000 mAh cm-2) is unprecedented, and records the highest performance reported for lithium-metal batteries with LLZO electrolytes till date.

Reference
ACS Energy Lett. 8, 9?20 (2023)
DOI
http://dx.doi.org/10.1021/acsenergylett.2c02150