Integration of gel polymer electrolytes with dry electrodes for quasi-solid-state batteries

Substituting liquid electrolytes with gel polymer electrolytes (GPEs) represents a viable solution to address safety concerns in lithium-ion batteries (LIBs). However, the inadequate interface between polymer electrolytes and thick electrodes leads to discontinuous charge transfer, elevated interface resistance, and reduced energy density. In this study, GPEs were integrated with high-mass-loading dry electrodes to realize quasi-solid-state batteries (QSSBs) with superior energy density and safety profiles. Traditional slurry electrodes impede electrolyte infiltration due to inconsistent particle and pore distribution, whereas the uniform pore structure and particle arrangement of dry electrodes enhance electrolyte permeability, enabling the establishment of a continuous ion transport network, homogenization of Li+ concentration and current density, and reduction of concentration polarization. As a result, the QSSB featuring a dry cathode (30 mg cm(-2)) exhibits impressive capacity retention of 80.9 % after 120 cycles, while even at 200 mg cm(-2), the cell maintains stability over 40 cycles with 73.7 % capacity retention. Furthermore, the pouch cell utilizing dry electrodes exhibits 83.7 % capacity retention after 45 cycles, demonstrating outstanding cycling performance and safety attributes. This research offers insights for the development of high-energy-density and high-safety QSSBs.