Poly(vinylidene fluoride)-Based Al Ion Conductive Solid Polymer Electrolyte for Al Battery

Abstract

Al ion conductive solid polymer electrolyte is prepared using poly(vinylidene fluoride) (PVdF) and AlCl 3 as a host polymer and Al ion salt, respectively. AlCl 3 salt can be dissolved into PVdF and uniformly distributed in the polymer up to F/Al ratio is 8. With further increase in the AlCl 3 content, a phase separation of AlCl 3 and PVdF is observed. It is noted that melting and amorphization temperatures of PVdF are also affected by the content of AlCl 3 . The melting temperature and promotion of crystallization of PVdF decrease with increase in AlCl 3 until F/Al to be 8. With further increase in AlCl 3 , the melting and crystallization temperature increase. Through FT-IR characterization, it is observed that characteristic frequency peaks relating CF vibration shift with addition of AlCl 3 , indicating that Al cation interacts with F in the PVdF host. The highest conductivity is 4.4 × 10 −4 S cm −1 at room temperature is achieved at F/Al ratio equaling 8. The cation transference number of this Al polymer electrolyte is 0.24 which is close to that of PVdF-based Li ion conductive polymer. The electrochemical stable window of the PVdF-AlCl 3 polymer at F/Al ratio of 8 is 0 ∼ 2.4 V vs. Al 3+ /Al. The electrochemical stable window covers redox voltages of most reported cathode materials for rechargeable Al batteries, implying that this PVdF-based polymer electrolyte can be a good candidate for the Al batteries.

Tough Polymer Gel Electrolytes for Aluminum Secondary Batteries Based on Urea: AlCl3, Prepared by a New Solvent-Free and Scalable Procedure

“…This includes, for instance, polyethylene oxide (PEO), polymethylmethacrylate (PMMA) or polyacrylonitrile (PAN) [ 11 , 12 , 13 , 14 ]. This view is supported by experiments showing that PEO based electrolytes [ 9 ] are not able to sustain electroplating of aluminum [ 16 ]. Some electroplating is seen in electrolytes prepared with PVDF [ 9 ], but the current is certainly very low.…”

“…Battery safety is much enhanced when using solid electrolytes because they avoid leaks of toxic or corrosive liquids, and they mitigate or even eliminate the dendritic growth of the reduced metal at the anode and the subsequent short-circuits. In the case of Li-ion, which is the most mature among all-solid battery technologies, and a source of inspiration for the newest ones, porous polymer separators, dense polymer gel electrolytes and inorganic electrolytes are the most explored approaches [ 8 , 9 , 10 , 11 ]. Each of these has its own advantages and drawbacks, but, probably the most balanced approach is the use of polymer gel electrolytes (PGE), because of the combination of high ionic conductivity, dendrite growth mitigation, leak elimination, and mechanical endurance.…”

“…To the best of our knowledge there is only one procedure reported to date able to produce polymer gel electrolytes suitable for aluminum secondary batteries [ 9 , 10 , 11 , 12 ]. In this procedure, the complex acrylamide-AlCl 3 is dissolved in dichloromethane, where it is polymerized in the presence of the ionic liquid electrolyte 1-ethyl-3-methylimidazolium chloride (EMImCl) and AlCl 3 (EMImCl: AlCl 3 , 1:1.5, in molar ratio).…”

Preparation of thin solid electrolyte by hot-pressing and diamond wire slicing

“…Ionic transference number of the thin LAGP solid electrolyte was measured by DC polarization technique. 28 A DC voltage of 1.0 V was applied to the Au/LAGP/Au cell. The ionic transference number (t i ) was calculated from initial current, I i and stabilized current, I f , using following equation:…”

Mechanical Integrity Degradation and Control of All-Solid-State Lithium Battery with Physical Aging Poly (Vinyl Alcohol)-Based Electrolyte

“…In contrast to inorganic counterparts with a brittle crystalline phase, the solid polymer electrolyte (SPE) exhibits excellent interfacial compatibility, and superior elasticity to endure greater mechanical deformation, contributing to be cast into the complicated architectures for lithium-ion and lithium-metal batteries [ 3 , 4 , 5 ]. Consequently, a wide array of polymers such as poly (ethylene oxide) (PEO) [ 6 , 7 , 8 , 9 ], polyacrylonitrile (PAN) [ 10 , 11 , 12 , 13 ], poly (vinylidene fluoride) (PVdF) [ 14 , 15 ], and its copolymer with hexafluoropropylene (PVdF-HFP) [ 16 , 17 ], poly (methyl methacrylate) (PMMA) [ 18 , 19 , 20 ], and poly (vinyl alcohol) (PVA) [ 21 , 22 , 23 , 24 ], as well as their mixtures [ 25 , 26 , 27 , 28 ], have been adopted as the potential matrices for solid electrolytes. Especially, the outstanding inherent advantages (nontoxicity, biocompatibility, biodegradable, good mechanical strength, relatively high dielectric constant, and charge storage capacity) of PVA make it one of the preferred choices for such applications [ 29 , 30 , 31 ].…”