Polymer binders for the electrodes of lithium batteries. Part 3. Conductive polymers

The third part of the review is devoted to polymer binders with electronic conductivity used to make composite electrodes for lithium electrochemical systems. Polymer semiconductors (“synthetic metals”), related polymers with additionally introduced functional groups, related copolymers and mixtures of polymers, as well as carbon chain polymers and copolymers with inсorporated polyaromatic fragments are considered. Such materials significantly improve electrical connectivity of the composite electrode and make it possible to eliminate or minimise the content of electrochemically inert conductive additives (carbon black, graphite powder), which positively influences on the specific capacity and cycling stability of the electrodes. Improving conditions of electronic transfer is especially important for the efficient use of active materials with extremely low intrinsic conductivity, such as Si, Li4Ti5O12, LiFePO4, etc. The final part of the review summarizes general principles of the targeted selection of a polymer binder.