Fast-Charging Lithium-Ion Pouch Cell by Constructing a Solid-Phase Lithium-Conducting Network in a Compacted Cathode

The fast charging capability of lithium (Li)-ion batteries (LIBs) is heavily dependent on the way Li-ion diffusion occurs within the electrode. The current status of using compacted cathodes for high volumetric energy density of LIBs, however, brings about the difficulty of high-rate operation due to insufficient ion diffusion originating from poor electrolyte infiltration in limited porosity. Here, we propose a strategy of constructing a solid-phase Li-conducting network by using Li6.4La3Zr1.4Ta0.6O12 additive to offset the inability of electrolyte infiltration into the compacted cathode. Insights into the way ion transport is carried out in the compacted cathode are further provided by X-ray computed tomography technology. Even at a 5 C rate, the modified cathode still exhibits a specific capacity of 97.9 mAh g-1, in contrast to the full electrochemical failure of the routine cathode. Besides, the practicality of this strategy has been confirmed in Li-ion pouch cells using a compacted cathode (120 μm thickness, 24 mg cm-2). This work may prove the potential of tuning Li transport pathways for the fast charging operation of compacted cathodes.