Improving Ionic Conductivity and Lithium-Ion Transference Number in Lithium-Ion Battery Separators

Abstract

The microstructure of lithium-ion battery separators plays an important role in separator performance; however, here we show that a geometrical analysis falls short in predicting the lithium-ion transport in the electrolyte-filled pore space. By systematically modifying the surface chemistry of a commercial polyethylene separator while keeping its microstructure unchanged, we demonstrate that surface chemistry, which alters separator-electrolyte interactions, influences ionic conductivity and lithium-ion transference number. Changes in separator surface chemistry, particularly those that increase lithium-ion transference numbers can reduce voltage drops across the separator and improve C-rate capability.

High‐Performance Gel Polymer Electrolyte Based on Chitosan–Lignocellulose for Lithium‐Ion Batteries

“…The lithium ion transference number ( t Li + ) is an important parameter of electrochemical performances for GPE. The current‐time curves of DC polarization and Nyquist plots before and after polarization are obtained with Li/GPE/Li cell in Figure .…”

Polyphenols assisted silica coating on polypropylene separators with improved wettability and heat‐resistance for lithium‐ion batteries

“…As shown in Table , the ion conductivity calculated using the equation is 0.63 mS cm −1 for the PG‐PP separator and 0.66 mS cm −1 for the SiO 2 ‐PP separator, which are both a bit higher than that of the bare separator (0.56 mS cm −1 ). This difference may arise from the well‐preserved pore structure (Figure ) and enhanced wetting capacity (Figure S3) of the porous substrates, which synergistically increase the electrolyte uptake and accordingly improve the ionic conductivity of PP separators . Electrochemical stability was tested by linear sweep voltammetry with SS/separator/Li cells.…”

Topological and network analysis of lithium ion battery components: the importance of pore space connectivity for cell operation

“…Similarly, other morphological and topological parameters are helpful when assessing surface interactions and effects. 31,35,41 Among such parameters are other Minkowski functionals, which correspond to a microstructure's surface area and curvature (described in detail in Sections 2 and 3 in the ESI †). Finally, lithium ion battery separators are just one example of a component in energy and environmental systems that can benefit from the topological and network analysis presented here.…”