Preparation and characterization of a special structural poly(acrylonitrile)-based microporous membrane for lithium-ion batteries

Abstract

In this work, a special structural poly(acrylonitrile) (PAN)-based microporous membrane for lithium-ion batteries is prepared from PAN emulsion by simple casting and extracting techniques. It is found that the microporous membrane is fabricated by PAN particles with uniform size (about 580 nm), and a lot of micropores exist among the particles. The Gurley number of the microporous membrane obviously depends on the amount of additive but the porosity does not. The PAN-based microporous membrane is activated by non-aqueous liquid electrolyte to form microporous gel electrolyte (MGE), and its ionic conductivity increases with the decrease of the Gurley number. The resulting MGE shows typical thermal shut-down action because of the swellingincorporating behaviors of PAN-based particles by the help of the solvent of liquid electrolyte at high temperature. In addition, the electrochemical stability window of the MGE can extend to 5.5 V vs. Li + /Li. The test cell using MGE as separator shows high initial discharge capacity (143 mAh g -1 based on LiCoO 2 ) and high capacity retention ratio (around 94.8% at the 50th cycle). Generally, the special structural microporous membrane is promisingly used to prepare highsafety lithium-ion batteries.

Compliant gel polymer electrolyte based on poly(methyl acrylate-co-acrylonitrile)/poly(vinyl alcohol) for flexible lithium-ion batteries

“…3. The obtained fracture strength of the membranes is 14.3 MPa, which is far higher than PAN [22] and P(MMA-co-AN) [23]. The stress-deformation curve of the PMA-based GPE is also investigated, and the fracture strength is only 6.11 MPa, demonstrating that the appropriate AN improved the mechanical strength of the membrane obviously, which is also in accordance with the previous reported [23].…”

Polyvinylidene fluoride‐co‐chlorotrifluoroethylene and polyvinylidene fluoride‐co‐hexafluoropropylene nanofiber‐coated polypropylene microporous battery separator membranes

“…Various approaches have been used to modify porous polyolefin membranes using coatings of thin layers of different materials. Examples of these approaches include, but are not limited to, lamination,9–12 dip coating,13–18 electrospinning,12, 19 spraying,20, 21 casting,22–25 and gravure 26–28. Among these various coating methods, electrospinning provides a simple and efficient technique to prepare nanofiber‐based porous coatings 19, 29–31.…”

Preparation of novel carbon microfiber/carbon nanofiber-dispersed polyvinyl alcohol-based nanocomposite material for lithium-ion electrolyte battery separator

“…The data emphasize the advantage of incorporating high tensile ACF/CNF within the polymeric film, and in addition, the use of surfactant for dispersing ACF/CNF. The tensile strength (2146 kg-f-cm −2 ) of PVA-S-BM-CNF obtained in this study may be compared to the same for a few commercial Li-ion battery separators: 1900 kg-f-cm −2 for Celgard-2325, 2100 kg-f-cm −2 for Celgard-2340, 1500 kg-f-cm −2 for Tonen-1 [2], 271 kg-f-cm −2 for PVdF-based material [30], and 53 kg-f-cm −2 -850 kg-f-cm −2 for composite cellulosic separator material [13]. From the presentation of the data in this section, we conclude that the mechanical strength of PVA-S-BM-CNF is superior to most of the commercially available separators and comparable to some.…”

“…The liquid electrolyte was prepared by mixing equal volumes (5 cm 3 ) of ethylene carbonate (EC) and dimethyl carbonate (DMC). The calibrated amount of LiPF 6 powder was added to the above liquid to prepare 1 M LiPF 6 solution [30]. The synthesized separator materials, PVA-M, PVA-S-BM-CNF, and PVA-SL-BM-CNF, were cut into small pieces (10 mm×10 mm) and dipped in the electrolyte at 35°C for 2 h. The (fabric) samples of ACF/CNF also were cut into the same dimensions and saturated with the electrolyte.…”

“…To our knowledge, the ionic conductivity (1.19 × 10 −1 S-cm −1 ) of PVA-S-BM-CNF obtained in this study is significantly larger than that in the literature data, for example, larger than 6.76 × 10 − 4 S-cm − 1 for the PAN-based separator [31], 1.95×10 −3 S-cm −1 for LLTO/PAN composite fiber [5], 3.1×10 − 5 S-cm − 1 for the MMA-modified PE separator [6], 3.92×10 −4 S-cm −1 for PVdF/HFP-based separator [32], and 8.90 × 10 −4 S-cm −1 for PVdF/PE-based separator material [30]. Table 1 also presents the data for PVA-S-BM-CNF, corresponding to type B measurements.…”