Fluoroethylene carbonate

In addition to carbonate solvents, partially flnorinated organic solvents have also been developed in parallel. It has been reported the chemical and electrochanical stability of solvents could be remarkably improved by the substitution of C-H bonds with C-F bonds [439,440]. Nanbu et al. [441] found that although the ionic conductivity of fluoroethylene carbonate (FEC) electrolyte containing 1 M TEABF4 was slightly lower than the PC-based electrolyte, the specific capacitance and rate performance achieved in the FEC-based electrolyte were improved compared to the PC-based electrolyte. It was also found the solubility of TEMABF4 in the FEC could... 

Nanbu, N., K. Suzuki, N. Yagi et al. 2007. Use of fluoroethylene carbonate as solvent for electric double-layer capacitors. Electrochemistry 75 607-610. 

Janes, A., T. Thomberg, J. Eskusson, and E. Lust. 2013. Fluoroethylene carbonate as co-solvent for propylene carbonate based electrical double layer capacitors. Journal of the Electrochemical Society 160 A1025-A1030. 

Kim, M., I. J. Kim, S. Yang, and S. Kim. 2014. Fluoroethylene carbonate addition effect on electrochemical properties of mixed carbonate-based organic electrolyte solution for a capacitor. Bulletin of the Korean Chemical Society 35 466-470. 

Nambu, N., R. Takahashi, M. Takehara, M. Ue, and Y. Sasaki. 2013. Electrolytic characteristics of fluoroethylene carbonate for electric double-layer capacitors at high concentrations of electrolyte. Electrochemistry 81 817—819. 

J. Kasnatscheew, R. W. Schmitz, R. Wagner, M. Winter, R. Schmitz, J. Electrochem. Soc. 2013, 160, A1369-1374. Fluoroethylene carbonate as an additive for y-butyrolactone based electrolytes. 

Ethylene carbonate (EC) and propylene carbonate (PC) have favorable physical and electrochemical properties such as high relative permittivity, high donicity, and relatively wide potential window. The direct fluorination of EC was successfully carried out to provide 4-fluoro-l,3-dioxolan-2-one (fluoroethylene carbonate, FEC) as shown in Scheme 2.3 [20], The fluorination of EC was strongly dependent on a choice of a reaction medium and no solvent was preferred from the viewpoint of conversion. FEC was further fluorinated to give three di-fluorinated derivatives. On the other hand, FEC was also prepared from 4-chloroethylene carbonate by exchange with KF [21], FEC was tested as an electrolyte additive for rechargeable lithium cells [21, 22] and is now practically used [23, 24],... 

McMillan, R. Slegr, H. Shu, Z. X. Wang, W., Fluoroethylene carbonate electrolyte and its use in lithium ion batteries with graphite anodes, J. Power Sources 1999, 81-82,20-26. 

ProfatUova, 1. A. Kim, S.-S. Choi, N.-S., Enhanced thermal properties of the solid electrolyte interphase formed on graphite in an electrolyte with fluoroethylene carbonate, Electrochim. Acta 2009, 54, 4445 450. 

In 1986, Sanyo Electric Company found that cyclic carbonates obtained by introducing halogens into EC can be used as solvents [84], which was followed by numerous reports on this topic [85-91]. In 1996, McMillan et al. from the National Research Council of Canada found an electrolyte that was compatible with graphite anode by utilizing fluoroethylene carbonate (60) [87] and propylene carbonate. The number of patent application for electrolytes consisting of fluoroethylene carbonate in combination with dinitrile compounds increased drastically around 2004. Details are described in Sect. 3.5.2 in the discussion of dinitriles. 

Several electrolyte additives have been used to form stable SEI layers and improve cyclability of silicon anodes. Doh et al. [Ill] used 5% 4-fluoroethylene carbonate (FEC) in the electrolyte of 1.0-M LiPFs in EC/DMC/EMC/PC at a volume ratio of 4 3 3 1 when investigating silicon/carbon composites formed by polyaniline carbonization. They found that the addition of FEC to the electrolyte increased the initial discharge capacity of the silicon/carbon composites when compared with the electrolyte without FEC. Choi et al. [112] reported that the... 

Choi NS et al (2006) Effect of fluoroethylene carbonate additive on interfacial properties of silicon thin-film electrode. J Power Sources 161 1254—1259... 

Functional electrolyte additives are included in the electrolyte solution to improve battery performance. This concept has been around for some time, tind the basic technology is well established. One early example is the addition of propane sultone to the nonaqueous electrolyte solution of a rechargeable battery using a metallic lithium anode. Although this technology was initially developed for metallic lithium batteries, the use of such additives for LIBs began around 1994. Since then a wide range of additives have been developed. So many different compounds have been used as additives that they are too numerous to mention, but notable examples include vinylene carbonate, propane sultone, phenylcyclohexane, and fluoroethylene carbonate. The selection of additives and determination of their appropriate formulations have become a key aspect of the proprietary know-how of each battery manufacturer, and the search for new additives continues apace. 

Chen X, Li X, Mei D, Feng J, Hu MY, Hu J, Engelhard M, Zheng J, Xu W, Xiao J, Liu J, Zhang J-G (2014) Reduction mechanism of fluoroethylene carbonate for stable solid-electrolyte interphase film on silicon anode. Chemsuschem 7 549-554. doi 10.1002/ CSSC.201300770... 

Etacheri V, Haik O, Goffer Y, Roberts GA, Stefan IC, Fasching R, Aurbach D (2012) Effect of fluoroethylene carbonate (EEC) on the performance and surface chemistry of Si-nanowire Li-ion battery anodes. Langmuir 28 965-976. doi 10.1021/la203712s... 

Fridman K, Sharabi R, Elazari R, Gershinsky G, Markevich E, Salitra G, Aurbach D, Garsuch A, Lampert J (2013) A new advanced lithium ion battery combination of high performance amorphous columnar silicon thin film anode, 5 V LiNio.sMni 5O4 spinel cathode and fluoroethylene carbonate-based electrolyte solution. Electrochem Commun 33 31-34. doi 10.1016/j.elecom.2013.04.010... 

Nakai H, Kubota T, Kita A, Kawashima A (2011) Investigation of the solid electrolyte interphase formed by fluoroethylene carbonate on Si electrodes. J Electrochem Soc 158 A798-A801. doi 10.1149/1.3589300... 

Park Y, Shin SH, Hwang H, Lee SM, Kim SP, Choi HC, Jung YM (2014) Investigation of solid electrolyte interface (SEI) film on LiCo02 cathode in fluoroethylene carbonate (EEC)-containing electrolyte by 2D conelation X-ray photoelectron spectroscopy (XPS). J Mol Struct 1069 157-163. doi 10.1016/j.molstnic.2014.01.041... 

Profatilova lA, Stock C, Schmitz A, Passerini S, Wintea- M (2013) Enhanced thermal stability of a lithiated nano-sihcon electrode by fluoroethylene carbonate and vinylene caibonate. J Power Sources 222 140-149. doi 10.1016/j.jpowsour.2012.08.066... 

The solid electrolyte interface formation process can be influenced by the use of electrolyte additives. Cyclic carbonates containing a vinyl group, such as vinylene carbonate, halogenated cyclic carbonates, such as fluoroethylene carbonate, and difluoroethylene carbonate have been used as electrolyte additives. Other additives are sUyl esters such as sultones, and esters of phosphoric and boric acid. 

The effects of a small amoimt of fluoroethylene carbonate C3H3FO3 on the electrochemical performance of a hthium-rich layered oxide cathode have been assessed (56). When 1% or 2% by volume of C3H3FO3 was introduced into the electrolyte, the cycling... 

Sulfonyldipropionitrile, cf. Figure 2.20, is structurally different from commonly used compoimds as additives for an LiMn204 cathode, e.g., tiis(pentafluorophenyl) borane (76), vinyl ethylene carbonate (77), fluoroethylene carbonate (78), hexamethyldisilaz-ane (79), tris(trimethylsilyl) borate (80), or tris(trimethylsilyl) phosphate (81). 

An electrolyte for a rechargeable lithium battery with excellent storage stability at a high temperature has been described (104). The electrolyte for a rechargeable lithium battery includes a nonaque-ous organic solvent, a lithium salt, and an additive. The additive includes vinylene carbonate, fluoroethylene carbonate, and a nitrile-based compound. 

When vinylene carbonate was included at an amount of 0.01-9% and fluoroethylene carbonate was included at an amount of 0.1-7%, and a nitrile-based compound, such as adiponitrile, was included in an amount of 0.005-10% to prepare an electrolyte, a cell including the electrolyte demonstrated an excellent storage stability even at a high temperature (104). 

When a fluoroethylene carbonate additive was introduced into the electrolyte, the MosSbz-C anodes exhibited a longer cyclic life with a capacity retention of aroimd 90% at 100 cycles, as well as a superior rate-cyclic performance corresponding to a capacity retention of more than 70% at 10,000 mA g. ... 

An important strategy to design suitable electrolyte systems has been shown that makes the desirable interfacial structure to allow the reversible sodiation and desodiation of SrqPs anodes (120). A remarkable improvement in the electrochemical performance of SrqPs anodes for sodium-ion batteries can be achieved by the combination of fluoroethylene carbonate with tris(trimethylsilyl) phosphite. 

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