POF3 Research Articles

Electrolyte recovery from spent Lithium-Ion batteries using a low temperature thermal treatment process

Electrolyte recovery is seldomly considered in state-of-art lithium-ion battery recycling methods but rather evaporates and decomposes uncontrolled during the pre-treatment steps. However, controlled and safe removal of the electrolyte is inevitable and of high importance to the recycling industry to minimize the environmental impact of the recycling processes by preventing severe threats produced by the inflammable, toxic and hazardous components of the electrolyte. This study investigated the effects of temperature and process time of a low temperature thermal treatment process on electrolyte recovery. The process exhaust gases and recovered products were analyzed by In-Situ Fourier-transform infrared spectroscopy (FT-IR) and gas chromatography-mass spectrometry (GC–MS) to determine the effectiveness of the significant process parameters. The results show that the electrolyte solvents, which are dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), and ethylene carbonate (EC), were successfully recovered for 80 minutes of processing time at 130 °C. The LiPF6 decomposition products hydrogen fluoride (HF) and phosphoryl fluoride (POF3) were detected in the exhaust gas stream and recovered as acidic solutions. Thermal treatment below 150 °C is a promising approach for the recovery of the electrolyte solvents prior to the metal recycling stage due to its simplicity, feasibility, and environmental benefit.

Performance Leap of Lithium Metal Batteries in LiPF6 Carbonate Electrolyte by a Phosphorus Pentoxide Acid Scavenger.

Phosphorus pentoxide (P2O5) is investigated as an acid scavenger to remove the acidic impurities in a commercial lithium hexafluorophosphate (LiPF6) carbonate electrolyte to improve the electrochemical properties of Li metal batteries. Nuclear magnetic resonance (NMR) measurements reveal the detailed reaction mechanisms of P2O5 with the LiPF6 electrolyte and its impurities, which removes hydrogen fluoride (HF) and difluorophosphoric acid (HPO2F2) and produces phosphorus oxyfluoride (POF3), OF2P-O-PF5- anions, and ethyl difluorophosphate (C2H5OPOF2) as new electrolyte species. The P2O5-modified LiPF6 electrolyte is chemically compatible with a Li metal anode and LiNi0.6Mn0.2Co0.2O2 (NMC622) cathode, generating a POxFy-rich solid electrolyte interphase (SEI) that leads to highly reversible Li electrodeposition, while eliminating transition metal dissolution and cathode particle cracking. The excellent electrochemical properties of the P2O5-modified LiPF6 electrolytes are demonstrated on Li||NMC622 pouch cells with 0.4 Ah capacity, 50 μm Li anode, 3 mAh cm-2 NMC622 cathode, and 3 g Ah-1 electrolyte/capacity ratio. The pouch cells can be galvanostatically cycled at C/3 for 230 cycles with 87.7% retention.

Toxicity analysis of second use lithium-ion battery separator and electrolyte

Pyrolysis gas chromatography-mass spectrometry (Py-GC-MS) test, smoke toxicity analysis and mouse biological toxicity test were carried out on the second use lithium-ion battery separator and electrolyte. It was found that the types of cracked products of separator and electrolyte under different state of health (SOH) were basically the same, mainly phosphoryl fluoride (POF3) and long-chain F-containing alkanes, alcohols and esters. The content of POF3 in the cracked product increases as the SOH increases. The toxic gas components released after the separator and the electrolyte are completely burned mainly include CO, CO2, and HF. The HF content decreased as the battery SOH decreased, from 101.6 mg/g of the 100% SOH battery to 44.1 mg/g of the 65% SOH battery. In the biological toxicity test, all the mice were found to stop running, close eyes, shed tears, and have shortness of breath. After the test, only 65% SOH and 100% SOH mice recovered their body weight to the pre-experimental average state and gained weight.

Lithium-ion battery electrolyte emissions analyzed by coupled thermogravimetric/Fourier-transform infrared spectroscopy

In the last few years the use of Li-ion batteries has increased rapidly, powering small as well as large applications, from electronic devices to power storage facilities. The Li-ion battery has, however, several safety issues regarding occasional overheating and subsequent thermal runaway. During such episodes, gas emissions from the electrolyte are of special concern because of their toxicity, flammability and the risk for gas explosion. In this work, the emissions from heated typical electrolyte components as well as from commonly used electrolytes are characterized using FT-IR spectroscopy and FT-IR coupled with thermogravimetric (TG) analysis, when heating up to 650 °C. The study includes the solvents EC, PC, DEC, DMC and EA in various single, binary and ternary mixtures with and without the LiPF6 salt, a commercially available electrolyte, (LP71), containing EC, DEC, DMC and LiPF6 as well as extracted electrolyte from a commercial 6.8 Ah Li-ion cell. Upon thermal heating, emissions of organic compounds and of the toxic decomposition products hydrogen fluoride (HF) and phosphoryl fluoride (POF3) were detected. The electrolyte and its components have also been extensively analyzed by means of infrared spectroscopy for identification purposes.

Toxic fluoride gas emissions from lithium-ion battery fires

Lithium-ion battery fires generate intense heat and considerable amounts of gas and smoke. Although the emission of toxic gases can be a larger threat than the heat, the knowledge of such emissions is limited. This paper presents quantitative measurements of heat release and fluoride gas emissions during battery fires for seven different types of commercial lithium-ion batteries. The results have been validated using two independent measurement techniques and show that large amounts of hydrogen fluoride (HF) may be generated, ranging between 20 and 200 mg/Wh of nominal battery energy capacity. In addition, 15–22 mg/Wh of another potentially toxic gas, phosphoryl fluoride (POF3), was measured in some of the fire tests. Gas emissions when using water mist as extinguishing agent were also investigated. Fluoride gas emission can pose a serious toxic threat and the results are crucial findings for risk assessment and management, especially for large Li-ion battery packs.

New Autoinductive Cascade for the Optical Sensing of Fluoride: Application in the Detection of Phosphoryl Fluoride Nerve Agents.

A new autoinductive cascade employing benzoyl fluoride as a latent source of fluoride is reported for signal amplification and optical detection of fluoride. The autoinduction leads to a maximum 4-fold signal enhancement for each fluoride generated, as well as a self-propagating cycle that generates three fluorophores for each single fluoride released. A two-step integrated protocol creates a more rapid autoinductive cascade than previously reported, as well as a highly sensitive diagnostic assay for the ultratrace quantitation of a phosphoryl fluoride nerve agent surrogate.

Crystal Structure and Spectroscopic Investigations of POF3

AbstractPhosphoryl fluoride was characterized by Raman spectroscopy and X‐ray diffraction analysis. The X‐ray structure was obtained by in‐situ crystallization. Phosphoryl fluoride crystallizes in the trigonal space group P$\bar{3}$m1 with two formula units in the unit cell. In the crystal structure zigzag chains are observed which are formed by intermolecular P–O contacts. The Raman spectra of neat and matrix isolated POF3 display an extra line, which indicates intermolecular interaction in the solid state. Therefore quantum chemically calculation of a POF3 oligomer was performed. The theoretical calculation indicates that the extra Raman line is caused by side splitting of the P–O valence vibration.

Thermal Decomposition of LiPF6-Based Electrolytes for Lithium-Ion Batteries

The thermal decomposition of lithium-ion battery electrolytes in one or more carbonate solvents has been investigated. Electrolytes containing diethyl carbonate (DEC), ethylene carbonate (EC), a 1:1 mixture of EC/dimethyl carbonate (DMC), and a 1:1:1 mixture EC/DMC/DEC have been investigated by multinuclear nuclear magnetic spectroscopy, gas chromatography with mass selective detection, and size exclusion chromatography. Thermal decomposition affords products including: carbon dioxide , ethylene , dialkylethers , alkyl fluorides (RF), phosphorus oxyfluoride , fluorophosphates , fluorophosporic acids , and oligoethylene oxides. The mechanism of decomposition is similar in all /carbonate electrolytes. Trace protic impurities lead to generation of , which autocatalytically decomposes and carbonates. The presence of DEC leads to the generation of ethylene, while the presnce of EC leads to the generation of capped oligothylene oxides .

Thermal stability of lithium-ion battery electrolytes

The thermal decomposition of LiPF 6 in the solid state and as solutions in dialkylcarbonates has been investigated. The thermal decomposition of LiPF 6 was investigated with differential scanning calorimatry (DSC) suggesting decomposition to LiF and PF 5. In solution, PF 5 reacts with dialkylcarbonates to form a variety of decomposition products including carbon dioxide (CO 2), ethers (R 2O), alkylfluorides (RF), phosphorus oxyfluoride (OPF 3), and fluorophosphates (OPF 2OR, OPF(OR) 2). The structure of the decomposition products are supported by nuclear magnetic resonance (NMR) spectroscopy and gas chromatography with mass selective detection (GC–MS).

MNDO-PM3 study on gas-phase alkaline hydrolysis of phosphoryl and thiophosphoryl fluorides

The gas-phase alkaline hydrolysis of phosphoryl and thiophosphoryl fluorides was theoretically examined by using the semiempirical MNDO-PM3 molecular orbital method. The potential-surface analysis showed that the facial attack of the hydroxide ion from the backside toward one of the P–F bonds was thermodynamically favored. The three trigonal bipyramidal and one square pyramidal pentacoordinate species were specified as stable intermediates by a reaction coordinate method. The vibrational analysis of transition states demonstrated that these permutational isomers were interconverted by Berry's pseudorotation process. The larger activation enthalpy of permutation was required for most pentacoordinate species from thiophosphoryl fluoride through permutation than phosphoryl fluoride. The apical departure of the fluoride ion from the pentacoordinate species was enegetically most favorable.

Forbidden rotational Q branch of OPF 3 observed by microwave Fourier transform spectroscopy

The pure rotational spectrum that becomes weakly allowed through centrifugal distortion mixing has been investigated between 8 and 26 GHz for phosphoryl trifluoride (OPF 3) in the ground vibronic state using a pulsed microwave Fourier transform spectrometer. The molecule is of particular interest because it is near spherical top. Ten Q-branch series following the (Δ k = ±3) selection rule have been obtained for a lower state K = ∥ k∥ between 5 and 18 with 24 ≤ J ≤ 94. The ( A 1 - A 2) splitting has been observed in OPF 3 for the first time. Splitting measurements have been made for the series k = ±9 ← ±6 and k = ±12 ← ±9. In addition, the allowed dipole transition ( J = 1, K = 0) ← (0, 0) has been measured with the same spectrometer. A total of 319 perpendicular transitions, this one parallel transition, and the 138 lines in the parallel R branch obtained earlier by Smith [ Mol. Phys. 32, 621–645 (1976)] have been treated with a weighted least-squares analysis. Determinations have been made of both rotational constants ( A and B), seven diagonal distortion constants ( D J , D JK , D K , H J , H JK , H KJ , and H K ), and two distortion constants (ϵ and ϵ J ) that characterize the (Δ k = ±3) matrix elements. The data set has been used to investigate the redundancies that exist in the quartic and sextic Hamiltonian for symmetric tops with small values of (A − B) 1 2 (A + B) . Pulsed double resonance methods have been extended to three-level systems for which the transition moment arises only from the centrifugal distortion mixing.

Behavior of phosphoryl trifluoride toward dry trimethylamine oxide: complex formation and disproportionation and action of Lewis acids

Behavior of phosphoryl trifluoride toward dry trimethylamine oxide: complex formation and disproportionation and action of Lewis acids

Reaction of phosphorus trifluoride and thiophosphoryl fluoride with iodine monochloride and oxidation of phosphorus trifluoride with nitryl chloride, iodic acid, periodic acid, sodium nitrite and potassium nitrite

Phosphorus trifluoride and thiophosphoryl fluoride both react smoothly with iodine monochloride at room temperature to form dichlorotrifluorophosphorane. The oxidants, nitryl chloride, iodic acid and periodic acid undergo reduction to nitrosyl chloride and iodine respectively, oxidising the phosphorus trifluoride to phosphoryl fluoride. The nitrite salts of sodium and potassium also undergo reduction at elevated temperatures(200°C) with phosphorus trifluoride and then react further with the formed phosphoryl fluoride to yield the corresponding monofluorophosphates of sodium and potassium.

Reactions of phosphorus trifluoride and thiophosphoryl fluoride with strong oxidizing agents

Facile oxidations of phosphorus trifluoride occur yielding a pentavalent phosphorus compound upon reaction with iodine monochloride, nitryl chloride, iodic acid and periodic acid. Reactions with sodium and potassium nitrites yield phosphoryl fluoride as a primary reaction product which further reacts to form corresponding monofluorophosphates along with the metal fluoride. Reactions of thiophosphoryl fluoride with iodine monochloride resembles closely that of phosphorus trifluoride in the formation of dichlorotrifluorophosphorane with elemental sulphur formed in addition. No reaction is observed with nitryl chloride. Details of these reactions will be presented.

An affinity gel for the inhibition, binding, and isolation of serine proteases

A preparation procedure for gels for the specific binding and inhibition of serine proteases is described. Phosphoryl trifluoride was synthesized and reacted with two different types of agarose gels, a crosslinked agarose (Sepharose CL-4B) and an agarose containing spacer arms with terminal vicinal-diol groups (a hydrolyzed epoxy-activated Sepharose 6B). The phosphoryl difluoride groups coupled to the gels were, in both cases, further modified by treatment with isopropanol to obtain isopropyl fluorophosphate groups covalently bound to the matrix. It was found that both modified gels adsorbed and inhibited plasmin, but that the modified gel with spacer arms was markedly more efficient.

ChemInform Abstract: REDUCTION OF PHOSPHORUS TRIFLUORIDE AND PHOSPHORYL FLUORIDE WITH LITHIUM ALUMINUM HYDRIDE

Chemischer InformationsdienstVolume 16, Issue 3 Preparative Inorganic Chemistry ChemInform Abstract: REDUCTION OF PHOSPHORUS TRIFLUORIDE AND PHOSPHORYL FLUORIDE WITH LITHIUM ALUMINUM HYDRIDE R. G. KALBANDKERI, Search for more papers by this authorD. K. PADMA, Search for more papers by this authorA. R. V. MURTHY, Search for more papers by this author R. G. KALBANDKERI, Search for more papers by this authorD. K. PADMA, Search for more papers by this authorA. R. V. MURTHY, Search for more papers by this author First published: January 22, 1985 https://doi.org/10.1002/chin.198503028Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume16, Issue3January 22, 1985 RelatedInformation

Reaction of thiophosphoryl fluoride with sulphur trioxide

Thiophosphoryl fluoride is observed to undergo a facile reaction with sulphur trioxide forming phosphoryl fluoride, sulphur dioxide and elemental sulphur in quantitative yields. In the presence of excess of sulphur trioxide, however, the elemental sulphur released combines with it to form sulphur sesquioxide which subsequently decomposes and gives off sulphur dioxide. Similar observations are made with oleum.

Energetics of the ionization and fragmentation of phosphorus oxyfluoride studied by electron-impact spectroscopy

The relative intensities and appearance energies of several positive ions in the mass spectrum of POF3 are reported together with an ionization-efficiency curve for F–, the only negative ion of significant intensity. Probable ion-fragmentation pathways are proposed together with the heats of formation of some positive ions and ionization energies for POF2 and POF. The appearance energies of various electronic states of the observed ions have been determined by deconvolution of the experimental ionization efficiency curves by the energy-distribution difference method.

PHOSPHORORGANISCHE VERBINDUNGEN 991VERSUCHE ZUR AUFKLÄRUNG DER O-SELEKTIVITÄT VON VERBINDUNGEN MIT DER P(O)F-GRUPPE

Abstract The mechanism of the reaction of phosphoryl fluoride ( P(O)F) with alcohols in the presence of an amine is fundamentally different from the reaction of phosphoryl chlorides ( P(O)Cl) with primary or secondary amines. The following observations strongly support this proposal: 1. 1H-NMR-, 31P-NMR- and 19F-NMR-spectroscopic investigations show that methyl-phenyl-phosphinicacid-fluoride and n-butylamine form a thermolabile adduct, which yields the methyl-phenyl-phosphinicacid-amide only very slowly. 2. The rate of the reaction of methyl-phenyl-phosphinicacid-fluoride with ethanol is independent of the basicity of the amine but very sensitive to steric factors. Imidazole (which is only a weak base) is surprisingly active. 3. The application of optically active amines as bases in the reaction of racemic methyl-phenyl-phosphinicacid-fluoride with methanol leads to partially optically active methyl-phenyl-phosphinicacid-methylester. This observation proves that the amines are incorporated in the intermed...

Champ de forces de symétrie locale des composés oxyfluorés du phosphore(V)—II. Le monofluorotrioxophosphate (M.F.P.) PO 3F 2− et le trifluorure de phosphoryle (T.F.P.) POF 3

The objective of this work was to assign systematically the normal modes of vibration of the phosphorous(V) oxyfluorates. These compounds are derived from the orthophosphates by successive substitution according to the sequence PO 3− 4→PO 3F 2−→PO 2F 2 −→POF 3 after consideration of PO 2F 2 − (D.F.P.), the work was extended to PO 3F 2− (M.F.P.) and phosphoryl trifluoride (T.F.P.). The a priori calculation of the vibrational frequencies of these species in a local symmetry force field yields very good agreement with the observed frequencies. Furthermore, the results of this vibrational study confirm the contracting effect of the fluorine atoms, which has already been shown by X-ray crystallography.