Propylene Carbonate Research Articles

Green Recovery of Cathode Active Materials from Li-Ion Battery Electrode Scraps Using Propylene Carbonate: A Novel Approach for Direct Recycling

Green Recovery of Cathode Active Materials from Li-Ion Battery Electrode Scraps Using Propylene Carbonate: A Novel Approach for Direct Recycling

New potential substitute of PVDF binder: poly(propylene carbonate) for solvent-free manufacturing high-loading cathodes of LiFePO4|Li batteries

New potential substitute of PVDF binder: poly(propylene carbonate) for solvent-free manufacturing high-loading cathodes of LiFePO4|Li batteries

Co-Solvent Electrolyte Design to Inhibit Phase Transition toward High Performance K+/Zn2+ Hybrid Battery.

Manganese hexacyanoferrate (MnHCF) is one of the most promising cathode materials for aqueous battery because of its non-toxicity, high energy density, and low cost. But the phase transition from MnHCF to Zinc hexacyanoferrate (ZnHCF) and the larger Stokes radius of Zn2+ cause rapid capacity decay and poor rate performance in aqueous Zn battery. Hence, to overcome this challenge, a solvation structure of propylene carbonate (PC)-trifluoromethanesulfonate (Otf)-H2O is designed and constructed. A K+/Zn2+ hybrid battery is prepared using MnHCF as cathode, zinc metal as anode, KOTf/Zn(OTf)2 as the electrolyte, and PC as the co-solvent. It is revealed that the addition of PC inhabits the phase transition from MnHCF to ZnHCF, broaden the electrochemical stability window, and inhibits the dendrite growth of zinc metal. Hence, the MnHCF/Zn hybrid co-solvent battery exhibits a reversible capacity of 118mAhg-1 and high cycling performance, with a capacity retention of 65.6% after 1000 cycles with condition of 1Ag-1. This work highlights the significance of rationally designing the solvation structure of the electrolyte and promotes the development of high-energy-density of aqueous hybrid ion batteries.

Engineering tannic acid with tailored structure into Poly(propylene carbonate) towards supramechanical performance and multi-functions

It's significant but challenging to prepare PPC with supramechanical performance and multi-functions. In this work, a mechanically robust, fluorescent, transparent and UV-shielding PPC composite is successfully prepared for the first time by incorporating a hydroxyalkylated tannin acid (mTA). Compared to TA, mTA shows an excellent compatibility to PPC due to the grafted plentiful flexible isopropanol oligomers with terminal hydroxyl group. The effects of content and grafting degree of mTA on the mechanical properties of PPC/mTA composites are investigated and the mechanism for the high strength and high toughness is revealed. By introducing 3 phr mTA with medium grafting degree (m-mTA), PPC/m-mTA3 shows a tensile strength of 23.38 ± 0.96 MPa and an elongation at break of 852 ± 37%, which is comparable to LDPE and LLDPE and implies the great potential of PPC to replace non-biodegradable PE materials. The supramechanical performance is the result of the combined multiple hydrogen bonding and plastic deformation zone originating from the excellent compatibility. Besides, Tg of mTA will affect the yield strength of PPC/mTA composites. More importantly, PPC/m-mTA film shows the fluorescent effect with dual-mode responsiveness, good UV-shielding effect and transparency, which will expand the application of PPC into advanced packaging materials. We envision that this work opens a novel yet facile way to prepare PPC with supramechanical performance and multi-functions, and will promote the practical application of PPC materials.

Modification of Cellulose Ether with Organic Carbonate for Enhanced Thermal and Rheological Properties: Characterization and Analysis.

Reduction in viscosity at higher temperatures is the main limitation of utilizing cellulose ethers in high thermal reservoir conditions for petroleum industry applications. In this study, cellulose ether (hydroxyethyl methyl cellulose (HEMC)) is modified using organic carbonates, i.e., propylene carbonate (PC) and diethyl carbonate (DEC), to overcome the limitation of reduced viscosity at high temperatures. The polymer composites were characterized through various analytical techniques, including Fourier-transform infrared (FTIR), H-NMR, X-ray diffraction (XRD), scanning electron microscope (SEM), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), ζ-potential measurement, molecular weight determination, and rheology measurements. The experimental results of structural and morphological characterization confirm the modification and formation of a new organic carbonate-based cellulose ether. The thermal analysis revealed that the modified composites have greater stability, as the modified samples demonstrated higher vaporization and decomposition temperatures. ζ-potential measurement indicates higher stability of DEC- and PC-modified composites. The relative viscometry measurement revealed that the modification increased the molecular weight of PC- and DEC-containing polymers, up to 93,000 and 99,000 g/moL, respectively. Moreover, the modified composites exhibited higher levels of stability, shear strength and thermal resistance as confirmed by viscosity measurement through rheology determination. The observed increase in viscosity is likely due to the enhanced inter- and intramolecular interaction and higher molecular weight of modified composites. The organic carbonate performed as a transesterification agent that improves the overall properties of cellulose ether (HEMC) at elevated temperatures as concluded from this study. The modification approach in this study will open the doors to new applications and will be beneficial for substantial development in the petroleum industry.

Transformed Solvation Structure of Noncoordinating Flame‐Retardant Assisted Propylene Carbonate Enabling High Voltage Li‐Ion Batteries with High Safety and Long Cyclability (Adv. Energy Mater. 28/2023)

Transformed Solvation Structure of Noncoordinating Flame‐Retardant Assisted Propylene Carbonate Enabling High Voltage Li‐Ion Batteries with High Safety and Long Cyclability (Adv. Energy Mater. 28/2023)

Ion transport in non-aqueous electrolyte mixtures of zinc chloride deep eutectic solvent (DES) and molecular solvents

The ion dynamics of null solvents 1ZnCl2:4EtG and 1ChCl:1ZnCl2:6EtG incorporating 1M water, propylene carbonate (PC) or acetonitrile (AcN) were investigated using 1H NMR spectra and spin-lattice relaxation time (T1) measurements combined with ionic conductivity, density, and viscosity, all as a function of temperature. Results show that the inclusion of all co-solvents increased the available free volume of the mixtures and followed the trend H2O ≤ PC < AcN. 1H NMR spectra and T1 inferred the presence of multiple ionic species with varying rates of mobilities. These dynamic heterogeneities were displayed by the broad T1 minima – especially for the 1ZnCl2:4EtG mixtures – and asymmetrically broadened linewidths. T1 results also revealed selective interaction sites between the hydrogen bond donors and acceptors, as well as with the co-solvents.

Solubilities of CO2, CH4, C2H6, CO, H2, N2, N2O, and H2S in commercial physical solvents from Monte Carlo simulations

ABSTRACT The removal of acid gas impurities from synthesis gas or natural gas can be achieved using several physical solvents. Examples of solvents applied on a commercial scale include methanol (Rectisol), poly(ethylene glycol) dimethyl ethers (Selexol), n-methyl-2-pyrrolidone (Purisol), and propylene carbonate (Fluor solvent). Continuous Fractional Component Monte Carlo (CFCMC) simulations in the osmotic ensemble were used to compute the Henry coefficients of the pure gases CO, CH, CH, CO, H, N, NO, and HS in the aforementioned solvents. The predicted Henry coefficients are in good agreement with the experimental results. The Monte Carlo method correctly predicts the gas solubility trend in these physical solvents, which obeys the following order: HS > CO > CH > CH > CO > N > H. The gas separation selectivities for the precombustion process and the natural gas sweetening process are calculated from the pure gas Henry coefficients. The CO/NO analogy is verified for the solubility in these solvents.

Study of isobaric vapor–liquid equilibria of diethyl carbonate + ethylene carbonate for lithium-ion battery electrolyte solvent recycling

The limited life-cycle of lithium-ion batteries (LIBs) remains a significant issue for the industry. Recycling electrolytes from the batteries is one crucial aspect of LIBs recycling, which can conserve resources and reduce environmental pollution. The vapor–liquid equilibrium (VLE) data and models for the currently widely used carbonates, such as ethylene carbonate (EC), dimethyl carbonate (DMC), propylene carbonate (PC), diethyl carbonate (DEC), and ethyl methyl carbonate (EMC), can play an important role in designing the recycling process. In this work, the VLE data of DEC and EC is measured for the first time. A sophisticated equation of state, the Perturbed-Chain Polar Statistical Associating Fluid Theory, is used to establish the VLE model, not only for the newly measured DEC and EC system but also for other carbonates and their mixtures. Through the discussion of how the molecular characteristics of carbonates influence the VLE behavior, the dipolar character of linear carbonate molecules has been revealed. This demonstrates the power and importance of sophisticated modelling approaches in investigating molecular behavior of electrolyte solvents in the context of LIB recycling. Hence, this work provides valuable experimental and model data for designing recycling processes of electrolyte solvents and offers molecular insight into carbonates.

The imidazole ionic liquid was chemically grafted on SBA-15 to continuously catalyze carbon dioxide to prepare propylene carbonate

The massive emission of carbon dioxide has led to the greenhouse effect. The preparation of propylene carbonate from carbon dioxide and propylene oxide can alleviate the environmental problems caused by carbon dioxide. In this paper, the supported ionic liquid (NMImBr-SBA-15) was prepared by chemical grafting with SBA-15 as the carrier, and NMImBr-SBA-15 was characterized by XRD, N2 adsorption-desorption, TGA, TEM and FT-IR. The effects of operating conditions on product yield and selectivity were investigated in a batch reactor, including CO2 pressure, catalyst dosage, reaction time and reaction temperature. The continuous catalytic performance of NMImBr-SBA-15 was systematically studied in a fixed bed reactor, which has guiding significance for the reaction design and scale-up process. In addition, the possible reaction mechanism was deduced by DFT calculation.

Oxidative carbonylation of propylene glycol to propylene carbonate by copper-based catalysts

BackgroundDevelopment of copper-based catalyst and associated reaction engineering for heterogeneous oxidative carbonylation of propylene glycol (PG) to optimize conversion and selectivity. Coupling reactions with reverse water-gas shift reaction is a good way of realizing CO2 utilization. MethodThe synthesis of propylene carbonate (PC) through the oxidative carbonylation of propylene glycol is carried out in a pressurized autoclave reactor using solid copper catalysts. Various types of copper and composite copper/ceria catalysts are prepared by coprecipitation or impregnation method. Significant findingsReaction temperature and the roles of sodium acetate (SA) and potassium iodide (KI) additives are systematically studied with pure copper to map out the optimum reaction condition, i.e., a 100 °C-reaction using 2.0 g of PG mixed with 8.0 g of solvent with 0.02 g of SA and 0.02 g of KI additives. Using this optimized condition, the copper and composite copper/ceria catalysts are investigated with the composite catalysts composed of metallic copper on ceria, showing the highest selectivity of 94.7% towards PC. These findings in this study should pave way for the development of practical industrial scale CO2 utilization processes.

Investigation of P3HT:WO3 hybrid electrochromic thin films prepared by solution blending doping

Although poly(3-hexylthiophene) (P3HT) is a promising p-type conjugating polymer to optimize optical and electrical properties, it is known to be chemically unstable. To overcome this unstability, WO3 incorporated P3HT hybrid thin films has been synthesized by very simple solution blending doping method. Different amounts of WO3 were added into the P3HT solution and the incorporation of WO3 particles was confirmed by scanning electron microscopy, atomic force microscopy, and photoluminescence spectroscopy. The electrochemical reactions in 1 M lithium perchlorate (LiClO4)/propylene carbonate (PC) were studied by cyclic voltammetry and by electrochemical impedance spectroscopy. With the increase amount of WO3 in P3HT, the electrochromic efficiency increases first and then decreases. The optimum concentration was found as 30 wt% of WO3. The efficient interaction and well distribution between WO3 and P3HT improves the capacitive properties and electrochromic performance resulting a 110% increase in coloration efficiency (from 220 cm2/C to 464 cm2/C). Moreover, WO3 doped hybrid films shows long-term cyclability than undoped P3HT films. Structural and electrochemical investigations suggest that the optimum amount of WO3 doping is an alternative way to obtain high performance and environmentally stable electrochromic devices.

Polymer electrolyte based on Nafion plasticized with carbonates and their ternary mixtures for sodium-ion batteries

The physicochemical properties and ionic conductivity of Nafion polymer membrane in sodium form plasticized with such organic solvents as ethylene carbonate (EC), propylene carbonate (PC), dimethyl carbonate (DMC) and their ternary mixtures were studied. According to the results of gravimetry, simultaneous thermal analysis, IR spectroscopy, small-angle X-ray scattering, voltammetry, and impedance spectroscopy, it was shown that the optimal plasticizer for Na-Nafion membrane among the studied systems is a ternary mixture with the composition EC/PC/DMC = 0.45/0.45/0.1. The polymer electrolyte based on Na-Nafion, plasticized with this ternary mixture, despite the lower electrochemical stability compared to the membrane swollen with EC, has the highest swelling degree of 31% and the ionic conductivity of 0.08 mS cm−1 at 20 °C, which is maintained even at −60 °C (6 × 10−8 S cm−1). The obtained values are comparable with the conductivity of the lithium form of Nafion. The possibility of using a membrane based on the sodium form of Nafion as an electrolyte in sodium and sodium-ion batteries was shown.

Effect of Residual Solvents on Properties of Composite Solid Electrolytes

Solid-state electrolytes (SSEs) can stabilize lithium (Li) metal anodes and achieve high energy density. However, they often suffer from solvent residues during the preparation. The residual solvent will affect the performance of SSEs. In this paper, we take Li1.5Al0.5Ge1.5P3O12 (LAGP)/Poly(propylene carbonate) (PPC) composite solid electrolyte (CSE) as an example, the content of the solvent residue of CSE prepared by the solution casting method and its effect on performance are investigated. The result reveals that the solvent content decreases with the increase of drying time. It still contains more than 5 wt % solvent even after vacuum drying for 48 h. The presence of residual solvent promotes the binding of lithium ions (Li+) and carbonyls, which is conducive to the transfer of Li+. When the residual solvent content is high, SSE has high ionic conductivity, cycling capacity, and excellent cycling stability. When the solvent content decreases, the electrochemical window becomes wider. This result is of great significance for the future regulation of SSE solvent content.

1,3,5-Trifluorobenzene endorsed EC-free electrolyte for high-voltage and wide-temperature lithium-ion batteries

Ethylene carbonate (EC) is susceptible to the aggressive chemistry of nickel-rich cathodes, making it undesirable for high-voltage lithium-ion batteries (LIBs). The arbitrary elimination of EC leads to better oxidative tolerance but always incurs interfacial degradation and electrolyte decomposition. Herein, an EC-free electrolyte is deliberately developed based on gradient solvation by pairing solvation-protection agent (1,3,5-trifluorobenzene, F3B) with propylene carbonate (PC)/methyl ethyl carbonate (EMC) formulation. F3B keeps out of inner coordination shell but decomposes preferentially to construct robust interphase, inhibiting solvent decomposition and electrode corrosion. Thereby, the optimized electrolyte (1.1 M) with wide liquid range (−70–77 °C) conveys decent interfacial compatibility and high-voltage stability (4.6 V for LiNi0.6Mn0.2Co0.2O2, NCM622), qualifying reliable operation of practical NCM/graphite pouch cell (81.1% capacity retention over 600 cycles at 0.5 C). The solvation preservation and interface protection from F3B blaze a new avenue for developing high-voltage electrolytes in next-generation LIBs.

Thermodynamics of 2-alkanol + polar organic solvent mixtures. I. Systems with ketones, ethers or organic carbonates

The mixtures 2-propanol or 2-butanol + n-alkanone, or + acetophenone, or + linear monoether, or + cyclic ether, or + linear organic carbonate, or + propylene carbonate have been investigated using thermodynamic data, and in terms of the Flory theory, and the Kirkwood-Buff integrals. The data considered are: excess molar enthalpies (HmE), volumes, entropies, and the temperature dependence ofHmE. The enthalpy of the 2-alkanol-solvent interactions have been determined, and the different contributions to HmE discussed. It is shown that HmE values of the 2-alkanol (fixed) + n-alkanone, or + linear carbonate mixtures change in the same manner that for n-alkanone, or linear carbonate + n-alkane (fixed) systems. In contrast, HmE values of 2-alkanol (fixed) + linear monoether or + n-alkane mixtures change similarly. This set of results suggests that solvent–solvent interactions are determinant in systems with n-alkanone or linear carbonate, while interactions between alcohol molecules are determinant in mixtures with linear monoethers. According to the Flory model, orientational effects in systems with a given 2-alkanol become weaker in the sequence: linear monoether > linear organic carbonate > n-alkanone, and are stronger in solutions with a cyclic monoether than in those with cyclic diethers, and in systems with acetophenone or propylene carbonate than in the mixtures with the corresponding linear solvents. Results obtained from the Kirkwood-Buff integrals are consistent with these findings. The application of Flory model reveals that orientational effects are similar in systems with 1- or 2-alkanols, with the exception of solutions with linear monoethers, where such effects are stronger in mixtures containing 1-alkanols. For the examined systems, the formalism of the Kirkwood-Buff integrals makes no meaningful distinction between solutions with 1-alkanols or 2-alkanols.

Hydrodynamics of gas–liquid flow in a capillary at elevated pressure: Implications for the fixation of CO2 into propylene carbonate in microreaction systems

It is an effective method to capture and utilize carbon dioxide (CO2) by using a microreactor to fix CO2 into propylene carbonate (PC). It is important to investigate the hydrodynamics of gas–liquid flow in order to ensure that the CO2 fixation in microreactor is operated under suitable conditions to obtain efficient mass transfer performance. However, few studies have been concerned with PC-CO2 two-phase flow in microreactors, especially at elevated pressures. Therefore, a high-pressure microreactor observation platform is established in this work to explore the hydrodynamics of PC-CO2 two-phase flow at a pressure range of 0.5–3.0 MPa. Three typical patterns such as bubbly flow, slug flow, and slug-annular flow were observed, and the flow pattern diagram at different pressures was plotted using WeG and WeL. The influence of the pressure on flow pattern transition lines was further discussed. Moreover, the effects of pressure on bubble size, liquid film thickness, bubble frequency, and gas volume fraction were investigated, as well as the corresponding correlation models. This work may provide guidance for the operation of gas–liquid microreactor at elevated pressure, especially for the fixation of CO2 into PC.

Photo-Electrical Tandem of Modulated Polyvinyl Alcohol Based Plasticized Solid Polymer Electrolyte Nanocomposite Films: Effect of Propylene Carbonate Contents

Plasticized solid polymeric electrolyte nanocomposites based on polyvinyl alcohol (PVA) incorporating Cs2CuO2 nanoparticles (NPs), electrolyte salt (LiClO4) and plasticizer (PC) were prepared via solution casting technique. The dynamic light-scattering histogram revealed that the prepared Cs2CuO2 NPs have a size in the range of 80-120 nm. The interaction between different components in PVA/Cs2CuO2/LiClO4-PC films (plasticized PVA-SPEs) were probed by FTIR, while the surface and structure were evaluated by SEM and XRD, which indicate to amorphous nature of plasticized PVA-SPEs. The thermal behavior of films was measured via TGA, where a partial decrease in the thermal stability of films was noticed with an increase of PC content in the PVA-SPEs. The highest conductivity achieved is 9.56X10-5 S/cm for PVA-SPEs containing 8wt% PC at 298K. The plasticized PVA-SPEs exhibited higher specific capacitance by two folds and photovoltaic efficiency by three folds compared to pure PVA matrix.

Preparation of controllable micro-nano fiber bundle asymmetric porous PLA-PPC ethyl acetate driving film by pre-freezing treatment

The intelligent organic solvent actuator can effectively avoid direct contact in hazardous environment, which has important research significance in the fields of soft robots, intelligent devices and sensing. The structure of organic solvent actuators usually has asymmetrical structure, but the preparation process of such structure is complex and difficult to realize. Herein, based on the wettability difference of polymers, the asymmetric porous polylactic acid (PLA)- poly propylene carbonate (PPC) driving films with micro-nano fiber bundles were prepared by the simple pre-freezing treatment. The ultra-fast reversible intelligent deformation response behavior was triggered in ethyl acetate solvent. The deformation properties, surface morphology and pore size could be adjusted by the preparation process (pre-freezing temperature and PPC content). The PLA-PPC film was prepared at −7 °C with 0.85 wt% PPC content. After being soaked in solvent for 3 s, the maximum bending degree (360°) and curvature (1.9 cm−1) were obtained. The potential application scenarios of intelligent driving materials were provided, the driving film was designed as bionic flower, artificial butterfly, gripper driver and controllable circuit switch, which proved the feasibility of driving film in practical applications.

Synthesis of dimethyl carbonate from methanol and propylene carbonate over the Ca-Zr catalyst modified by transition metals

A series of Ca-Zr catalysts modified by different transition metals were prepared by the sol-gel method and their catalytic performance in the synthesis of dimethyl carbonate (DMC) from methanol and propylene carbonate (PC) by transesterification at low temperature was investigated. The results indicate that the selectivity to DMC of various transition metal-modified Ca-Zr catalysts follows the order of Co-Ca-Zr > Cu-Ca-Zr > Ca-Zr > Fe-Ca-Zr > Ni-Ca-Zr > Zn-Ca-Zr. For the transesterification over the Co-Ca-Zr catalyst, in particular, the conversion of PC reaches 84.3% with a selectivity of 94.5% to DMC after reaction for 2 h under 35 °C, a methanol/PC molar ratio of 15, and catalyst amount of 4%. Combining with the XRD, FT-IR, XPS and CO2-TPD results, it is revealed that increasing the strength of basic sites can raise the conversion of PC, whereas increasing the density of basic sites leads to a decrease of the selectivity to DMC. As a result, the Co-modified Ca-Zr (Co-Ca-Zr) catalyst, with the lowest density of surface basic sites but the highest fraction of strong basic sites, exhibits a high conversion of PC and a high selectivity to DMC for the transesterification of PC with methanol at a low temperature.