Low Resistance–Integrated All‐Solid‐State Battery Achieved by Li7La3Zr2O12 Nanowire Upgrading Polyethylene Oxide (PEO) Composite Electrolyte and PEO Cathode Binder

• Published in: Advanced functional materials 2019-01, Vol.29 (1), p.n/a
• Main Authors: Wan, Zipei, Lei, Danni, Yang, Wei, Liu, Cheng, Shi, Kai, Hao, Xiaoge, Shen, Lu, Lv, Wei, Li, Baohua, Yang, Quan‐Hong, Kang, Feiyu, He, Yan‐Bing
• Format: Article
• Language: English
• Subjects: Batteries; Cathodes; Dendritic structure; Electrochemical analysis; Electrolytes; Electrolytic cells; Energy storage; High temperature; integrated all‐solid‐state batteries; Interface stability; Ion currents; Li metal anodes; Lithium; Lithium batteries; LLZO microparticles; LLZO nanowires; Low resistance; Materials science; Molten salt electrolytes; Nanowires; Polyethylene; Polyethylenes; Short circuits; Solid electrolytes
• ISSN: 1616-301X; 1616-3028
• DOI: 10.1002/adfm.201805301

All‐solid‐state lithium metal battery is the most promising next‐generation energy storage device. However, the low ionic conductivity of solid electrolytes and high interfacial impedance with electrode are the main factors to limit the development of all‐solid‐state batteries. In this work, a low resistance–integrated all‐solid‐state battery is designed with excellent electrochemical performance that applies the polyethylene oxide (PEO) with lithium bis(trifluoromethylsulphonyl)imide as both binder of cathode and matrix of composite electrolyte embedded with Li7La3Zr2O12 (LLZO) nanowires (PLLN). The PEO in cathode and PLLN are fused at high temperature to form an integrated all‐solid‐state battery structure, which effectively strengthens the interface compatibility and stability between cathode and PLLN to guarantee high efficient ion transportation during long cycling. The LLZO nanowires uniformly distributed in PLLN can increase the ionic conductivity and mechanical strength of composite electrolyte efficiently, which induces the uniform deposition of lithium metal, thereby suppressing the lithium dendrite growth. The Li symmetric cells using PLLN can stably cycle for 1000 h without short circuit at 60 °C. The integrated LiFePO4/PLLN/Li batteries show excellent cycling stability at both 60 and 45 °C. The study proposed a novel and robust battery structure with outstanding electrochemical properties. A low resistance–integrated all‐solid‐state Li metal battery with excellent electrochemical performance is designed. The structure not only guarantees high ionic conductivity and good mechanical properties to suppress lithium dendrite growth by using polyethylene oxide (PEO)/lithium bis(trifluoromethylsulphonyl)imide embedded with Li7La3Zr2O12 nanowire composite electrolyte, but also decreases the interfacial impedance by applying PEO in both electrolyte and cathode that can fuse during operation.