Li7La3Zr2O12-co-LiNbO3 Surface Modification Improves the Interface Stability between Cathode and Sulfide Solid-State Electrolyte in All-Solid-State Batteries

Shishuo Liang; Dong Yang; Jianhua Hu; Shusen Kang; Xue Zhang; Yanchen Fan

doi:10.3390/membranes13020216

Li₇La₃Zr₂O₁₂-co-LiNbO₃ Surface Modification Improves the Interface Stability between Cathode and Sulfide Solid-State Electrolyte in All-Solid-State Batteries

Membranes (Basel). 2023 Feb 9;13(2):216. doi: 10.3390/membranes13020216.

Authors

Shishuo Liang^{1

2}, Dong Yang¹, Jianhua Hu¹, Shusen Kang², Xue Zhang³, Yanchen Fan^{4

5

6}

Affiliations

¹ State Key Laboratory of Molecular Engineering of Polymer, Department of Macromolecular Science, Fudan University, Shanghai 200438, China.
² Sunwoda Electric Vehicle Battery Company, Shenzhen 518107, China.
³ College of Resources and Environment, Jilin Agricultural University, Changchun 130118, China.
⁴ Petro China Shenzhen Renewable Energy Research Institute Co., Ltd., Shenzhen 518000, China.
⁵ CNPC Shenzhen New Energy Research Institute Co., Ltd., Shenzhen 518000, China.
⁶ SUSTech Academy for Advanced Interdisciplinary Studies, Department of Materials Science & Engineering, Southern University of Science and Technology, Shenzhen 518055, China.

Abstract

With the rapid development of energy storage and electric vehicles, thiophosphate-based all-solid-state batteries (ASSBs) are considered the most promising power source. In order to commercialize ASSBs, the interfacial problem between high-voltage cathode active materials and thiophosphate-based solid-state electrolytes needs to be solved in a simple, effective way. Surface coatings are considered the most promising approach to solving the interfacial problem because surface coatings could prevent direct physical contact between cathode active materials and thiophosphate-based solid-state electrolytes. In this work, Li₇La₃Zr₂O₁₂ (LLZO) and LiNbO₃ (LNO) coatings for LiCoO₂ (LCO) were fabricated by in-situ interfacial growth of two high-Li⁺ conductive oxide electrolytes on the LCO surface and tested for thiophosphate-based ASSBs. The coatings were obtained from a two-step traditional sol-gel coatings process, the inner coatings were LNO, and the surface coatings were LLZO. Electrochemical evaluations confirmed that the two-layer coatings are beneficial for ASSBs. ASSBs containing LLZO-co-LNO coatings LiCoO₂ (LLZO&LNO@LCO) significantly improved long-term cycling performance and discharge capacity compared with those assembled from uncoated LCO. LLZO&LNO@LCO||Li₆PS₅Cl (LPSC)||Li-In delivered discharge capacities of 138.8 mAh/g, 101.8 mAh/g, 60.2 mAh/g, and 40.2 mAh/g at 0.05 C, 0.1 C, 0.2 C, and 0.5 C under room temperature, respectively, and better capacity retentions of 98% after 300 cycles at 0.05 C. The results highlighted promising low-cost and scalable cathode material coatings for ASSBs.

Keywords: LLZO-coating; LiCoO2; LiNbO3-coating; solid-state batteries; sulfide solid-state electrolyte.

Grants and funding

This research was funded by the National Natural Science Foundation of China (No. 51773042 and 51973040) and China Postdoctoral Science Foundation (No. 2022M722214).