Polyacrylonitrile Porous Membrane-Based Gel Polymer Electrolyte by In Situ Free-Radical Polymerization for Stable Li Metal Batteries

Abstract

Because of their high ionic conductivity, utilizing gel polymer electrolytes (GPEs) is thought to be an effective way to accomplish high-energy-density batteries. Nevertheless, most GPEs have poor adaptability to Ni-rich cathodes to alleviate the problem of inevitable rapid capacity decay during cycling. Therefore, to match LiNi0.8Co0.1Mn0.1O2 (NCM811), we applied pentaerythritol tetraacrylate (PETEA) monomers to polymerize in situ in a polyacrylonitrile (PAN) membrane to obtain GPEs (PETEA-TCGG-PAN). The impedance variations and key groups during the in situ polymerization of PETEA-TCGG-PAN are investigated in detail. PETEA-TCGG-PAN with a high lithium-ion transference number (0.77) exhibits an electrochemical decomposition voltage of 5.15 V. Noticeably, the NCM811|PETEA-TCGG-PAN|Li battery can cycle at 2C for 120 cycles with a capacity retention rate of 89%. Even at 6C, the discharge specific capacity is able to reach 101.47 mAh g–1. The combination of LiF and Li2CO3 at the CEI interface is the reason for the improved rate performance. Moreover, when commercialized LFP is used as the cathode, the battery can also cycle stably for 150 cycles at 0.5C. PETEA and PAN can together foster the transportation of Li+ with the construction of a fast ion transport channel, making a contribution to stable charge–discharge of the above batteries. This study provides an innovative design philosophy for designing in situ GPEs in high-energy-density lithium metal batteries.

Polymers with Cyanoethyl Ether and Propanesulfonate Ether Side Chains for Solid-State Li-Ion Battery Applications

“…Figure shows the XPS spectra in the Li 1s, S 2p, C 1s, N 1s, O 1s, and F 1s regions. The peak in the Li 1s region at 55.3 eV is attributed to Li + ; the three peaks in the S 2p region at 163.6 eV (S–C), 168.5 eV (S–N), and 169.6 eV (SO); ,, the five peaks in the C 1s regions at 284.8 eV (C–C/CH), 286.6 eV (C–O), 287 eV (CN), 288.9 eV (C–S), and 292.4 eV (C–F); ,− the two peaks in the N 1s at 399.1 eV ( N –S) and 402.7 eV (NC); , the two peak in O 1s at 531.9 eV (OS) and 532.7 eV (O–C); , and the peak in F 1s at 688.3 eV (F–C) . Based on XPS analysis, all the peaks are attributed to the PVA–CN–SO 3 /LiTFSI SPE, while there is no apparent peak of the surface interphase electrolyte (e.g., LiF, Li 2 O, and R–COOLi) observed.…”

“…Figure 12 shows the XPS spectra in the Li 1s, S 2p, C 1s, N 1s, O 1s, and F 1s regions. The peak in the Li 1s region at 55.3 eV is attributed to Li + ; 64 399.1 eV (N−S) and 402.7 eV (N�C); 66,69 the two peak in O 1s at 531.9 eV (O�S) and 532.7 eV (O−C); 37,70 and the peak in F 1s at 688.3 eV (F−C). 66 Based on XPS analysis, all the peaks are attributed to the PVA−CN−SO 3 /LiTFSI SPE, while there is no apparent peak of the surface interphase electrolyte (e.g., LiF, Li 2 O, and R−COOLi) observed.…”

Recent progress and applications enabled via electrochemically triggered and controlled chain-growth polymerizations

“…In recent decades, with the development of polymer synthesis technologies, a number of synthetic methods enabling precise control of molecular weight have been discovered. 17 However, free radical polymerization (FRP) is still the most industrially relevant method, employed in the preparation low-density polyethylene, 18 polystyrene, 19 polyvinyl chloride, 20 polymethyl methacrylate, 21 polyacrylonitrile, 22 polyvinyl acetate, 23 styrene–butadiene rubber, 24 nitrile rubber, 25 neoprene, 26 etc . In conventional FRP, the reaction process can be divided into four main steps.…”

Tailoring of Li/LATP-PEO Interface via a Functional Organic Layer for High-Performance Solid Lithium Metal Batteries

“…Nowadays, lithium-ion batteries based on organic liquid electrolytes are increasingly unable to support the rapid development of portable electronics and electric vehicles due to their limited specific capacity and uncontrollable safety issues. − Replacing the liquid electrolyte with a solid-state electrolyte (SSE) and directly utilizing the lithium metal anode, solid-state lithium batteries (SSLBs), possessing high specific capacity and safety, are considered to be a promising next-generation energy storage system. − For developing SSLBs, it is essential to explore an effective SSE with a high ionic conductivity and Li + transfer number, wide electrochemical stability window, and good chemical/electrochemical compatibility with electrodes. − …”