High-voltage all-solid-state lithium metal batteries prepared by aerosol deposition

High-energy-density and safe rechargeable batteries are key components to realizing a low-carbon society. All-solid-state Li-metal batteries have the potential to achieve both high safety and high energy densities. However, the large interfacial resistance between solid electrolytes and cathodes is the major challenge for developing all-solid-state Li-metal batteries. Here we deposited a Li-rich layered metal oxide Li1.2Mn0.54Ni0.13Co0.13O2 (LMNC) thin film (6 µm thick) on an Al-doped Li7La3Zr2O12 (LLZO) substrate at room temperature by aerosol deposition. The LMNC particles were coated with Li3BO3 (LBO), which acted as a binder to hold LMNC and LLZO together at heating. As a result, good interfacial contact was achieved between LMNC and LLZO. Yet reactions between LMNC and LBO would occur at heat treatment temperatures above 600 °C. The highest discharge capacity of the all-solid-state Li/LLZO/LBO-LMNC cell at 0.1 C and 60 °C was 223 mAh g-1. The main reason for the cell capacity decay was the cracking of the LBO-LMNC cathode layer during cycling. Searching for a more suitable binder material with a high fracture toughness is crucial for further developing the aerosol-deposited LLZO-based all-solid-state Li metal batteries.