Polymer Interface-Dependent Morphological Transition toward Two-Dimensional Porous Inorganic Nanocoins as an Ultrathin Multifunctional Layer for Stable Lithium–Sulfur Batteries

Abstract

Two-dimensional (2D) porous inorganic nanomaterials have intriguing properties as a result of dimensional features and high porosity, but controlled production of circular 2D shapes is still challenging. Here, we designed a simple approach to produce 2D porous inorganic nanocoins (NCs) by integrating block copolymer (BCP) self-assembly and orientation control of microdomains at polymer–polymer interfaces. Multicomponent blends containing BCP and homopoly­(methyl methacrylate) (hPMMA) are designed to undergo macrophase separation followed by microphase separation. The balanced interfacial compatibility of BCP allows perpendicularly oriented lamellar-assembly at the interfaces between BCP-rich phase and hPMMA matrix. Disassembly of lamellar structures and calcination yield ultrathin 2D inorganic NCs that are perforated by micropores. This approach enables control of the thickness, size, and chemical composition of the NCs. 2D porous and acidic aluminosilicate NC (AS-NC) is used to fabricate an ultrathin and lightweight functional separator for lithium–sulfur batteries. The AS-NC layer acts as an ionic sieve to selectively block lithium polysulfides. Abundant acid sites chemically capture polysulfides, and micropores physically exclude them, so sulfur utilization and cycle stability are increased.

Enhanced Polysulfide Conversion with Highly Conductive and Electrocatalytic Iodine‐Doped Bismuth Selenide Nanosheets in Lithium–Sulfur Batteries

“…Taking into account the similar morphology of I-Bi 2 Se 3 and Bi 2 Se 3 , the enhanced lithium-ion diffusivities must be related to the improved catalytic activity of the former, which accelerates the LiPS conversion, and to the stronger LiPS adsorption that suppresses the shuttle effect and prevents the deposition of an insulating layer at the anode side. [52] To further analyze the electrocatalytic activity of the different materials toward the polysulfide conversion, CV profiles were measured on symmetric cells within the voltage window −1.0 to 1.0 V and using a 0.5 M Li 2 S 6 electrolyte (Figure 3h). [5,34] To eliminate the capacitive contribution, the CV curve of I-Bi 2 Se 3 in a Li 2 S 6 -free electrolyte was also measured as a reference (Figure S12, Supporting Information).…”

“…Taking into account the similar morphology of I‐Bi 2 Se 3 and Bi 2 Se 3 , the enhanced lithium‐ion diffusivities must be related to the improved catalytic activity of the former, which accelerates the LiPS conversion, and to the stronger LiPS adsorption that suppresses the shuttle effect and prevents the deposition of an insulating layer at the anode side. [ 52 ]…”

In Situ Separator Modification with an N-Rich Conjugated Microporous Polymer for the Effective Suppression of Polysulfide Shuttle and Li Dendrite Growth

“…During discharge, S 8 molecules first accept electrons and form long-chain LiPS (Li 2 S n ) at the upper plateau region, i.e., the first voltage plateau (>2.1 V). The LiPS has high chemical reactivity and the most severe shuttle effect at the upper plateau region, which leads to fast capacity fade and short cycle life. − Thus, the upper plateau discharge capacity (419 mA h g –1 in theory) evaluation can serve as a pre-evaluation of the LiPS-inhibiting capability. , Thus, the upper plateau capacity reflects LiPS-inhibiting capability. The battery with the NCMP@PP separator has a high initial upper plateau capacity (404 mA h g –1 ) and a high residual capacity (253 mA h g –1 ) after 800 cycles (Figures a and S16).…”

Porous Polymer Cubosomes with Ordered Single Primitive Bicontinuous Architecture and Their Sodium–Iodine Batteries

“…Porous polymers have recently attracted tremendous interest owing to their potential applications in various fields, including energy storage and conversion, catalysis, and gas adsorption. − Pore structure is one of the crucial factors determining the physiochemical properties and corresponding applications of porous materials. − Therefore, the generation of precise and controllable pore structures is decisive in porous polymers. − …”