Hierarchically porous and conductive LiFePO4 bulk electrode: binder-free and ultrahigh volumetric capacity Li-ion cathode

Due to the large volume fraction of electrochemically inactive materials involved in conventional thin calendered electrodes, it is challenging to approach high volumetric capacity. Here, we report a proof-of-concept study on LiFePO4-based bulk electrodes, as opposed to conventional thin calendered electrodes. The bulk electrodes are hierarchically porous, electro-conductive, metal current collector- and polymeric binder-free. In combination with 3D pore topologies and electronic conduction, even with a small quantity of conductive agents (5.6 wt%), the as-prepared bulk electrodes exhibit an ultrahigh volumetric capacity and a stable cycling life.