A sandwich‐structured separator based on in situ coated polyaniline on polypropylene membrane for improving the electrolyte wettability in lithium‐ion batteries

Abstract

Summary Designing separators with excellent electrolyte wettability is of great significance to improve the electrochemical behavior of lithium‐ion batteries (LIBs). Herein, we develop a sandwich‐structured separator by facile in situ polymerization of polyaniline (PANI) on the both sides of polypropylene (PP) separator. The introduction of PANI coating improves the electrolyte wettability of the PP separators. Consequently, the cells equipped with this sandwich‐structured separator demonstrate superior electrochemical performance including initial capacity, rate performance, and cyclic stability compared with the PP separator. This work may provide a facile approach for separator modification to improve the performance of LIBs.

Direct Fabrication of PET-Based Thermotolerant Separators for Lithium-Ion Batteries with Ion Irradiation Technology

“…ITE PET and PP separators were placed in Li|Li coin cells, a method commonly used to probe the Li + planting/stripping process. 12,51 As shown in Figure S13, the ITE PET separator ensures excellent cycling stability over 1500 h with an average overpotential of about 168 mV. Nevertheless, PP has inhomogeneous pores, which will lead to inhomogeneous lithium deposition, further accelerating the growth of Lidendrites, with significant fluctuations during the cycling period of 270−320 h.…”

“…In addition, EIS spectra of the LFP/separator/Li coin cells employing the PP and ITE PET separators are analyzed to investigate the interfacial resistance of the separators. , Figure b exhibits the Nyquist plots of LFP/separator/Li cells at the open-circuit potential. The interfacial resistances of the PP and ITE PET separators are measured as 116 and 105 Ω, respectively, evident from the semicircle observed in the high-middle-frequency region.…”

Intrinsically conducting polymers and their combinations with redox-active molecules for rechargeable battery electrodes: an update

“…Enhanced conductivity of PANI by incorporation of polyethyleneoxide has been reported (Yang et al 2017), this may possibly be useful for enhancing current-carrying properties of electrode materials. Coating of a polypropylene separator with PANI increased wetting with a nonaqueous electrolyte solution resulting in increased ionic conductance (Hao et al 2019). Coating of a polyethylene separator with particles of AlF 3 and a copolymer of EDOT and ethylene glycol yielded decreased thermal shrinkage and improved electrolyte solution uptake resulting in improved cycling performance (Shin et al 2015).…”

Study on modification and failure of precast solid electrolyte interface film on Li metal anodes

“…7 However, some serious defects, such as high reactivity, infinite volume change, unstable solid-electrolyte interface (SEI), "dead lithium" production, and dendrites growth, lead to low coulombic efficiency, high electrode impedance, short cycle life, and safety issues, which greatly hinder the large-scale application of metallic lithium. 8 In response to the above-mentioned shortcomings, researchers have developed a variety of solutions including using a new type of current collector to reduce the true current density of the Li anode, [9][10][11][12] modificating the current collector surface to improve its lithiumphilic performance, [13][14][15] covering an artificial SEI film on the surface of the Li to inhibit dendrites and reduce the side reactions between Li and the electrolyte, [16][17][18] using the new type of separator, 19,20 uniform distribution of Li-ion flux and inhibit the growth of lithium dendrites, developing new electrolyte solvents, 21,22 lithium salts 23,24 , additives, 25 solid electrolyte, 26,27 and so on. 28,29 Although these measures have delayed the failure of the Li anode, the positive effect is limited, and there are still difficulties in industrialization.…”