A Polymer‐Sol Binder Realizes Single‐Particle Binding for Nacre‐Like Piezoelectric Nanocomposites and Component‐Integrated Batteries

Abstract

Achieving precisely defined and stable component binding is of great interest for composite materials and batteries, but very challenging owing to the lack of effective strategies to manipulate the binder itself. Here, a concept of single‐particle binding (SPB) strategy is proposed based on a polymer‐sol binder to conquer the above challenge. To do that, a polymer‐sol binder is first prepared by dispersing commercial poly(vinylidene fluoride) (PVDF) powder into a mixture of its solvent and non‐solvent with a rational weight ratio of 8:2. Then, by manipulating this PVDF‐sol microfluid, PVDF particles are uniformly and singly introduced onto the surface of other components, such as graphene oxide nanosheets and battery separators. Results further show that the temperature‐induced sol–gel transition of the microfluid finally generates single‐particle fusion and strong component binding with commercial separators (31.6 N m−1). Meanwhile, a surface‐swelling model is proposed to understand its binding mechanism. Finally, this unique SPB strategy has been employed to fabricate nacre‐like nanocomposites with advanced self‐polarized piezoelectricity (23.0 mV N−1), and component‐integrated batteries with robust separator/electrode interphases. This SPB strategy with the PVDF‐sol binder may inspire significant studies on polymer sol, microfluidics, nanocomposites, battery interfaces and beyond.