Constructing Hybrid Solid–Liquid Li+ Transport Networks for Fast-Charging Thick Electrodes

Abstract Fast-charging technology for high-energy-density lithium-ion batteries remains constrained by high interfacial impedance and sluggish Li+ transport within electrodes. Herein, hierarchical-sized Li1.5Al0.5Ti1.5(PO4)3 (LATP, particle ranging from 5 to 500 nm) is used to construct a hybrid solid–liquid Li+ transport network in high-mass-loading cathodes (27 mg cm–2). A combination of different characterization techniques is employed to understand the underlying working principle of LATP from the particle to the electrode scale. LATP nanograins (∼10 nm) adsorbed onto cathode particle surfaces reduce Li+ desolvation energy (43.30 vs 52.97 kJ mol–1) and stabilize a thin CEI after cycling. Submicron LATP particles (320–480 nm) infiltrate pores of thick electrodes, forming interconnected networks that increase the Li+ diffusion coefficient. Furthermore, LATP increases the Li+ transference number of the liquid electrolyte within LATP-permeated regions. Consequently, LiNi0.8Co0.1Mn0.1O2||Li cells with LATP-blended cathodes deliver dramatically enhanced rate performance (102 vs 36 mAh g–1 at 0.75C and –10 °C).