Faster and better: A polymeric chaperone binder for microenvironment management in thick battery electrodes

Achieving high-performance thick battery electrodes via cost-efficient way is crucial for next-generation lithium/sodium ion batteries. However, the challenge comes from both a poor understanding of electrode microstructures and the lack of industry-friendly strategies on regulating the microstructures during the electrode fabrication. Here, as inspired by the chaperone in biology, a polymeric chaperone binder is reported to efficiently regulate the electrode microstructures. Firstly, the polymeric chaperone binder is realized by alloying poly(vinylidene fluoride) (PVDF) with ultra-high molecular weight poly(ethylene oxide), which generates unprecedented binder performance as compared with PVDF binder. Consequently, high-quality thick electrodes with a high active material (AM) loading around 60 mg/cm(2) (about 2 times of the commercial level) are fabricated with over 80% reduction of energy consumption in slurry drying process. Meanwhile, the microstructures and properties of AM microenvironment are further characterized by micro-probe scanning, electro-rheology and bending testing, for the first time. Finally, thick electrodes with a high areal capacity of 8 mAh/cm(2) @0.1C, superior C-rate and cycling performance have been demonstrated. In short, this study not only proposes an industry-friendly binder design strategy, but also uncovers the critical roles of binder solution in controlling the AM microenvironment quality and so the overall electrochemical performance.

Automated summary

This study reports a polymeric chaperone binder for regulating electrode microstructures. The binder enables the fabrication of high-quality thick electrodes with reduced energy consumption and demonstrates excellent performance. The microstructures and properties of the active material microenvironment are characterized, and thick electrodes with high areal capacity and superior performance are demonstrated.