Preparation of Poly-1-butene Nanofiber Mat and Its Application as Shutdown Layer of Next Generation Lithium Ion Battery

Abstract

Nonwoven nanofiber webs from polyolefin show great potential in various fields such as nanofilters, high performance membranes and separators in lithium ion batteries (LiB). Although nonwoven microfiber webs can be obtained by the well-established melt-blown method, it is relatively difficult to produce nonwoven nanofiber web using polyolefin (polyethylene and polypropylene). There have been several reports on the preparation of polyolefin nanofibers by melt-electrospinning, although this approach presents several intrinsic disadvantages, i.e., high processing costs, the requirement of complex equipment, and poor control over pore size or fiber diameter. Solution-based electrospinning has the potential to overcome the drawbacks of melt-electrospinning, but the solubility of most polyolefin is poor. In this study, we found that poly-1-butene, a member of the poly(alpha-olefin) family, can be used in the electrospinning process. We set the concentration of the polymeric solution for electrospinning at 0.65–1.7 g/mL. Here, we report on the fabrication of nonwoven fiber webs composed of poly-1-butene and their copolymers. The diameter of the nonwoven fiber mat was 0.2–0.4 μm, which can be applicable for shutdown layer. As a representative application, we prepared a poly-1-butene nanofiber separator with an appropriate pore size by electrospinning for use as the shut-down layer of a next-generation LiB. The PB-based nanofiber mat provided shutdown ability at around 100 to 120 °C.

Advances of polyolefins from fiber to nanofiber: fabrication and recent applications

“…Moreover, it has better solubility among olefin family members ensuring the easy electrospinning [ 247 , 248 ]. Jeong et al [ 230 ] prepared an electrospun fibrous mat using homo and copolymer of poly-1-butene (PB) on a polyethylene terephthalate (PET) support and proposed as a potential battery separator. By adjusting the monomer ratio in the copolymer of PB the melting point can be altered.…”

“…Currently, LiB has received much more attention in the energy source market due to its high durability, larger power density, and good electrochemical properties [229]. This type of battery is commonly used to operate various portable devices like electrically powered cars, computers, phones, and other electric gadgets [230][231][232][233]. Different parts of a LiB are demonstrated in Fig.…”

Advances in Electrospun Materials and Methods for Li-Ion Batteries

“…For 100 cycles of testing, the cyclic stability across 1 C and 5 C discharge rates was excellent. Non-woven separators of PE fabricated by other processes, such as the melt blown process, have a larger pore size which is not efficient for the shutdown process, but electrospinning leads to the synthesis of nanofibers of smaller diameter; however, in the synthesis process, the PE has poor solubility to the solvent; thus, more soluble Poly-1-butene Nanofiber was used for the electrospinning [ 74 ], and it has other properties similar to that of PE. This Polyethylene based separator was highly suitable as it possesses the required shutdown properties, and by adjusting the proportion of the polymers (monomer, copolymer) present, the melting point can be altered as well.…”

Recent Progress in Preparing Nonwoven Nanofibers via Needleless Electrospinning

“…Additionally, Lee's group recently demonstrated the application of the nanofiber for the separator of lithium‐ion battery (LIB). [ 30 ] They prepared nanofiber using poly‐1‐butene, and then represented the shutdown properties of the LIB separator.…”