Ion Selective Covalent Organic Framework Enabling Enhanced Electrochemical Performance of Lithium–Sulfur Batteries

Abstract

Ion selective separators with the capability of conducting lithium ion and blocking polysulfides are critical and highly desired for high-performance lithium−sulfur (Li−S) batteries. Herein, we fabricate an ion selective film of covalent organic framework (denoted as TpPa-SO 3 Li) onto the commercial Celgard separator. The aligned nanochannels and continuous negatively charged sites in the TpPa-SO 3 Li layer can effectively facilitate the lithium ion conduction and meanwhile significantly suppress the diffusion of polysulfides via the electrostatic interaction. Consequently, the TpPa-SO 3 Li layer exhibits excellent ion selectivity with an extremely high lithium ion transference number of 0.88. When using this novel functional layer, the Li−S batteries with a high sulfur loading of 5.4 mg cm −2 can acquire a high initial capacity of 822.9 mA h g −1 and high retention rate of 78% after 100 cycles at 0.2 C. This work provides new insights into developing high-performance Li−S batteries via ion selective separator strategy.

Regulating Li+ migration and Li2S deposition by metal-organic framework-derived Co4S3-embedded carbon nanoarrays for durable lithium-sulfur batteries

“…As shown in Fig. S10, the cell with Co 4 S 3 /C@CC also has the lowest ohmic resistance after cycling, reflecting the lower polysulfide viscosity in the electrolyte and the mitigated Li 2 S 1/2 passivation on the interlayer [39]. The lower polysulfide viscosity and the more effective Li 2 S 1/2 deposition can alleviate the shuttle effect of polysulfides and accelerate the Li + migration, hence boosting the battery performance.…”

Recycling respirator masks to a high-value product: From COVID-19 prevention to highly efficient battery separator

“…MF functionalized by FSA (S-MF) has three types of chemical groups that can be transformed by sulfonic groups, according to previous studies. Abundant sulfonic groups can form metal–SO 3 complexes with metal ions, which can offer improved ion transport when used as a battery separator [10] , [11] . With increasing modification time of MF by FSA, the intensity of the specturms which presented –OH and –SO 3 H groups increased based on the FT-IR spectra ( Fig.…”

Boosting Polysulfide Catalytic Conversion and Facilitating Li+ Transportation by Ion‐Selective COFs Composite Nanowire for LiS Batteries

“…[39] However, the drawbacks of COFs include poor film-forming property, cumbersome preparation steps, and low electronic conductivity that need to be urgently solved. [39,40] Efforts have been implemented to address some of the drawbacks, including graphene mixed with lithiated COFs, [34] ionic-COFs in situ growth on MXene, [30] added carbon-based layers, [41] etc., which improved the film-forming property and increased the electrical conductivity of COFs. However, mechanical mixing and uneven growth of COFs in conductive materials continue to cause partial aggregation of ions and electrons, while unattainable largescale production and rare exploration of the catalytic conversion of LiPSs by COFs need to be addressed.…”