Solid-state lithium metal batteries based on ceramic and polymer composite electrolytes

Solid-state Li metal batteries hold the promise to greatly boost conventional Li-ion battery technologies; being capable of storing more energy as well as being safe from combustion. However, replacing the ubiquitous liquid... [ view full abstract ]

Solid-state Li metal batteries hold the promise to greatly boost conventional Li-ion battery technologies; being capable of storing more energy as well as being safe from combustion. However, replacing the ubiquitous liquid electrolyte in a Li-ion battery, by a solid electrolyte is great scientific challenge. The poor contact and the highly resistive interfaces between the solid electrolyte and the solid electrodes are a major limitation for practical application. This contribution reports on the development and prospective solutions of solid-state Li metal batteries. We first focus on Li₇La₃Zr₂O₁₂ (LLZO) garnet electrolyte, and investigate the interfacial limits with Li metal anode in symmetrical cell and full cell configuration. After prolonged cycling, unexpected deposition of Li metal dendrites occurs within the ceramic electrolyte, leading to short-circuit and cell failure [1]. The mechanisms of dendrite formation and propagation through the ceramic electrolyte will be discussed.

Then, two promising alternatives to full ceramic electrolytes will be presented, based on a) soft interlayers and b) elastic polymer-ceramic membranes. This combination of hard-soft electrolyte materials is found to greatly enhance the interfacial stability with Li metal anode upon cycling, offering new opportunities to prevent Li dendrite formation in solid-state batteries.

References

[1] F. Aguesse, W. Manalastas, L. Buannic, J. M. Lopez del Amo, G.Singh, A. Llordés, J. Kilner. Investigating the Dendritic Growth during Full Cell Cycling of Garnet Electrolyte in Direct Contact with Li Metal. ACS Applied Materials & Interfaces, 9 (4), 3808–3816, (2017).