High-Strength Poly(ethylene oxide) Composite Electrolyte Reinforced with Glass Fiber and Ceramic Electrolyte Simultaneously for Structural Energy Storage

The development of structural energy-storage materials is critical for the lightweighting and space utilization of electric vehicles and aircrafts. However, a structural electrolyte suitable for structural energy devices is rarely exploited. Here, a structural lithium battery composed of a fiber-reinforced structural electrolyte and a structural cathode is demonstrated. Benefitting from poly(ethylene oxide)–lithium bis(trifluoromethane)sulfonimide (PEO-LiTFSI) as the polymer electrolyte matrix and lithium aluminum titanium phosphate (LATP) and glass fiber (GF) as reinforcement fillers, the LATP-GF/PEO-LiTFSI composite electrolyte developed offers a high tensile strength of 33.1 MPa, large Li+ transfer number of 0.37, moderate ionic conductivity of 6.3 × 10–5 S cm–1 (at 25 °C), wide electrochemical window of 4.4 V, and high effectiveness in suppression of lithium dendrite growth. Finally, a structural lithium battery is demonstrated with acidified carbon fibers (ACFs) as the cathode, Li as the anode, and LATP-GF/PEO-LiTFSI as the electrolyte, which shows an ultrahigh tensile strength of 124.2 MPa and a moderate capacity of 1.45 mAh cm–2. Importantly, the ACF|LATP-GF/PEO-LiTFSI|Li cell can properly function under a high compressive stress of 11.26 MPa. It is believed that the design strategy with a fiber-reinforced polymer as the structural electrolyte and a carbon fiber woven fabric as the structural electrode is feasible to obtain high-performance structural energy-storage components.