Anion-Sorbent Composite Separators for High-Rate Lithium-Ion Batteries

Novel composite separators containing metal–organic-framework (MOF) particles and poly(vinyl alcohol) are fabricated by the electrospinning process. The MOF particles containing opened metal sites can spontaneously adsorb anions while allowing effective transport of lithium ions in the electrolyte, leading to dramatically improved lithium-ion transference number t_Li⁺ (up to 0.79) and lithium-ion conductivity. Meanwhile, the incorporation of the MOF particles alleviates the decomposition of the electrolyte, enhances the electrode reaction kinetics, and reduces the interface resistance between the electrolyte and the electrodes. Implementation of such composite separators in conventional lithium-ion batteries leads to significantly improved rate capability and cycling durability, offering a new prospective toward high-performance lithium-ion batteries.