Ultrathin solid polymer electrolyte enabling mechanically-strong energy storing fiber reinforced composites

• Published in: Composites science and technology 2023-11, Vol.244, p.110319, Article 110319
• Main Authors: Chen, Yifan, Xie, Tianming, Dai, Tengfei, Qiao, Xinfeng, Fu, Yu, Li, Yan
• Format: Article
• Language: English
• Subjects: Composite structural batteries; Electro-mechanical properties; Solid polymer electrolyte
• ISSN: 0266-3538
• DOI: 10.1016/j.compscitech.2023.110319

Structural batteries attract enormous research interest due to their advantages of integrated energy storage function in structure. Superior to the co-cured composite structural batteries based on glass fiber supported/reinforced liquid/low-strength polymer electrolyte, enhanced mechanical strength of solid polymer electrolyte would enable the facile fabrication of composite structural batteries through layer-by-layer stack up of composites and solid-state batteries. This work encloses a mechanically strong and self-supportive solid polymer electrolyte with a tensile strength of 9.28 MPa, significantly superior to the traditional PEO (Lithium salt) electrolyte. Systematic analysis of phase-microstructure-mechanical/electrochemical properties relationship of SPE with different fluoroethylene carbonate (FEC) amounts helps to find out a solid polymer electrolyte (SPE) with satisfactory ionic conductivity (0.35 × 10−4 S/cm) and high electrochemical stability window (4.6 V vs Li/Li+), based on which dimension-adaptable and mechanically-strong energy storing laminates which have high tensile strength of 343 MPa, tensile modulus of 30.6 GPa, flexural strength of 308 MPa, and high impact resistance have been successfully fabricated. The most surprising result is a capacity retention of as high as 67% of the original capacity in the 1st cycle and stable cycling of composite structural batteries over 50 cycles for the failed tensile sample, which points out its potential application in emergency rescue. We believe this work not only presents a facile method to fabricate solid polymer electrolytes but demonstrates the potential of this solid polymer electrolyte in facile fabrication of mechanically-strong composite structural batteries. Based on the newly-developed mechanically strong and self-supportive solid polymer electrolyte membrane, dimension-adaptable energy-storing laminates with outstanding mechanical properties have been successfully fabricated. The composite structural battery can surprisingly light up a LED after tensile failure. The failed composite structural battery demonstrates a capacity retention of as high as 67% of the original capacity in the 1st cycle after tensile failure and can stably cycle over 50 cycles. Underlying mechanism behind the outstanding resilience is the well-bonded electrode/electrolyte interface, without which the high potential of the newly developed composite structural battery in some extreme and emergent cases cannot be pr