Protecting lithium metal anode in all-solid-state batteries with a composite electrolyte

• Published in: Rare metals Vol. 40; no. 2; pp. 409 - 416
• Main Authors: Wei, Wen-Qing, Liu, Bing-Qiang, Gan, Yi-Qiang, Ma, Hai-Jian, Cui, Da-Wei
• Format: Journal Article
• Language: English
• Published: Beijing Nonferrous Metals Society of China 01.02.2021; Springer Nature B.V
• Subjects: Anodes; Anodic protection; Biomaterials; Chemistry and Materials Science; Dendritic structure; Electrolytes; Electrolytic cells; Energy; Fourier transforms; Ion currents; Ion transport; Lithium; Lithium ions; Low cost; Materials Engineering; Materials Science; Metallic Materials; Nanoscale Science and Technology; Original Article; Particulate composites; Physical Chemistry; Polyethylene oxide; Polymer matrix composites; Rechargeable batteries; Silicon nitride; Solid state; Symmetric cell; Composite electrolyte; Lithium dendrite growth; Lithium metal anode
• ISSN: 1001-0521; 1867-7185
• DOI: 10.1007/s12598-020-01501-6

The volume of the metallic lithium anode in all-solid-state Li metal batteries increases significantly due to the lithium dendrite formation during the battery cycling, and the rough surface of lithium metal also reduces Li-ion transport in Li/electrolyte interface. In this work, we developed a solid polymer composite by adding the low-cost Si 3 N 4 particles to protect the lithium anode in all-solid-state batteries. The Fourier transform infrared spectroscopy (FTIR) data show that the surface of 10 wt % Si 3 N 4 particles interacts with the polyethylene oxide (PEO) and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) salt; the interaction restricts the anion mobility and improves the ionic conductivity (1 × 10 −4 S·cm −1 ) and lithium-ion transference number (0.28) of the composite electrolyte. The lithium metal anode is well protected by the composite electrolyte in all-solid-state cells, including symmetric and Li/LiFePO 4 cells. The lithium dendrite growth suppression by this composite electrolyte indicates the possible application of these low-cost composite electrolytes for lithium metal protection. Graphic abstract