Speaker
Description
Binders play an important role in multi-component electrodes for rechargeable batteries, which suffer from poor electronic and ionic conductivity. Binder-free electrodes provide another way to resolve problems, where sophisticated structure construction is required. A new concept of electrode processing alternative to binder-containing and binder-free electrodes was established. A multi-functional PIM-1 (a polymer with intrinsic microporosity) additive was used instead of PVDF to form mechanically processable Li secondary battery cathodes. Due to its unique nanoporous structure built by the spiro-containing rigid aromatic polymer chain, only a tiny amount of PIM-1 in the LiNi0.8Co0.1Mn0.1O2 cathode is needed to retain good performance, far below the typical composition for PVDF. Homogeneous dispersion of carbon black is achieved by PIM-1, which stabilizes the electrode and increases the electronic conductivity. Different from PVDF, mechanical buffering by stiff PIM-1 yields crack-free electrodes after cycles. Moreover, an inorganic rich cathode-electrolyte interface layer is formed via a desolvation process promoted by PIM-1, because of its strong binding ability with lithium ions, which is beneficial for cyclic stability and rate capability.
