Triggering Ion Diffusion and Electron Transport Dual\nPathways for High Efficiency Electrochemical Li<sup>+</sup> Extraction

Efficient\nelectrochemical Li<sup>+</sup> adsorption holds significant\npromise for lithium extraction, while the mismatched rate between\nLi<sup>+</sup> diffusion and electron transport within the electrode\nmaterial impedes the electrochemical activity and restricts the adsorption\nefficiency. To address this challenge, herein, we rationally design\nand integrate the ion and electron dual-conducting poly(vinyl alcohol)–polyaniline\n(PVA-PANI) copolymer (CP) within the H<sub>1.6</sub>Mn<sub>1.6</sub>O<sub>4</sub> (HMO) electrode matrix to facilitate Li<sup>+</sup> diffusion and electron transport. The Li<sup>+</sup> diffusion coefficient\n(<i>D</i><sub>Li+</sub>) increased from 3.03 × 10<sup>–10</sup> to 5.92 × 10<sup>–10</sup> cm<sup>2</sup>/s, while the charge transfer resistance (<i>R</i><sub>ct</sub>) decreased from 53.73 to 29.57 ohm. Consequently, the HMO@CP\nelectrode exhibits superior adsorption kinetics and a state-of-the-art\nhigh adsorption capacity of up to 49.48 mg/g. Comprehensive mechanistic\nstudies reveal that the negatively charged hydroxyl groups (−OH)\nin PVA accelerate Li<sup>+</sup> diffusion and that the conjugated\nstructure and redox-active quinoid sites in PANI offer denser electron\ndistribution and promote electron transport. This synergistic effect\nin CP significantly enhanced Li<sup>+</sup> diffusion and electron\ntransport, leading to electrochemical activity and adsorption efficiency.\nOur work highlights the critical role of simultaneously regulating\nthe ion diffusion and electron transport dual pathways for optimizing\nLi<sup>+</sup> adsorption performance and inspires development of\nthe next generation electrochemical adsorption electrodes.