MOF particles (UiO-66 and UiO-66(Ce))/cellulose nanocomposite separators with regulating ion transport controllably for lithium battery

Abstract

Commercial separators result in poor lithium battery performance due to low electrolyte wettability and non-selective ion transport. In this work, the cellulose membrane with excellent electrolyte wettability was selected as the skeleton, and the MOF nanoparticles were added by the blending method. The composite cellulose membrane with uniform pore size was prepared by casting process. The cellulose membrane skeleton promoted the absorption of electrolytes. The Lewis acid sites presented in UiO-66 facilitated the dissociation of lithium salts by attracting PF₆⁻ anions. The OMS (open metal site) provided by UiO-66(Ce) further adsorbs anions and solvent molecules, effectively regulated ion transport, maintained a stable and efficient cycle life, and reduced lithium dendrite deposition. The LiFePO₄/Li equipped with UiO-66/CM showed a capacity retention rate of 71.70%, while the LiFePO₄/Li equipped with UiO-66 (Ce)/CM showed a capacity retention rate of 93.80 % after 200 cycles at 0.5C. Therefore, the developed strategy may provide a powerful way to improve electrolyte wettability and effectively regulate ion transport.