Poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene): A New Binder for Conventional and Printable Lithium-Ion Batteries

The growing interest in printable batteries leads to the necessity of developing new and more efficient materials that meet the required processability and performance characteristics. In this work, a poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene) (P(VDF-TrFE-CFE)) terpolymer has been used for the first time as a polymer binder for lithium-ion battery cathodes and their electrochemical characteristics have been compared with cathodes prepared with the commonly used poly(vinylidene fluoride), P(VDF), polymer binder. The rheological analysis shows that the inks show suitable properties to be printed by direct ink writing (DIW). Printing parameters were optimized with respect to the printing cathode line distance, and it is shown that the printed cathodes allowed to achieve improved battery performance when compared with conventional doctor blade-prepared electrodes, with a maximum discharge capacity of 147 mAh·g–1 at a C/8 rate. Further, it is shown that the P(VDF-TrFE-CFE) terpolymer as a new polymer binder leads to improved cathode performance (90 mAh·g–1 at a 1C rate) when compared with cathodes prepared with the commercial P(VDF) binder (80 mAh·g–1 at the 1C rate) under the same preparation method. Thus, it is shown that P(VDF-TrFE-CFE) represents a suitable binder for a new generation of high-performance batteries.