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 Li_6.4La₃Zr_1.4Ta_0.6O₁₂ 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.