Preparation Of Polymer Electrolytes Research Articles

Chitosan-based gel polymer electrolytes for high performance Li-ion battery

This study explores the use of glutaraldehyde-crosslinked chitosan-based gel polymer electrolytes (GPEs) in lithium-ion batteries (LIBs). GPEs are prepared by solution casting using two different molecular weights of chitosan including 150 kDa as medium and 400 kDa as high molecular weight (MMWCS and HMWCS, respectively) with varying amounts of crosslinker. Degree of crystallinity was 25.9 and 24.1 % for HMWCS and MMWCS, respectively that was decreased to 18.3 and 22.7 % by using 5 % crosslinker and 17.8 and 21.1 % by using 10 % crosslinker, and 17.2 and 17.6 % by using 20 % crosslinker. The obtained ionic conductivity for HMWCS and MMWCS was 3.1 × 10−3 and 2.9 × 10−3 S.cm−1. After crosslinking by 5, 10, and 20 % crosslinker, the ionic conductivity was obtained to 0.9 × 10−3 and 0.3 × 10−3 S.cm−1, 6.3 × 10−3 and 5 × 10−3 S.cm−1, and 1.1 × 10−3 and 0.5 × 10−3 S.cm−1 for high and medium molecular weight, respectively. Lithium-ion transfer number was obtained between 0.34 and 0.83 and the highest t+ value was obtained for the MMWCS-GA10. Electrochemical stability window of the prepared polymer electrolytes was >5 V and samples showed no remarkable dendrite growth after cycling analyses. The symmetric cells demonstrated reliable performance, operating for over 300 h without any short-circuiting, which indicates excellent reversible cycling stability for chitosan-based lithium-ion batteries. Furthermore, the Gr/GPE cell exhibited very low voltage polarization, with the over-potential decreasing from 10 mV initially to 6 mV after 300 h at the same current density. Discharge capacity was obtained higher than 170 mAh/g at 0.2C with CE = 97 % for both HMWCS-GA20 and HMWCS-GA20.

Stable Efficient Solid-State Supercapacitors and Dye-Sensitized Solar Cells Using Ionic Liquid-Doped Solid Biopolymer Electrolyte.

As synthetic and nonbiodegradable compounds are becoming a great challenge for the environment, developing polymer electrolytes using naturally occurring biodegradable polymers has drawn considerable research interest to replace traditional aqueous electrolytes and synthetic polymer-based polymer electrolytes. This study shows the development of a highly conducting ionic liquid (1-hexyl-3-methylimidazolium iodide)-doped corn starch-based polymer electrolyte. A simple solution cast method is used to prepare biopolymer-based polymer electrolytes and characterized using different electrical, structural, and photoelectrochemical studies. Prepared polymer electrolytes are optimized based on ionic conductivity, which shows an ionic conductivity as high as 1.90 × 10-3 S/cm. Fourier transform infrared spectroscopy (FTIR) confirms the complexation and composite nature, while X-ray diffraction (XRD) and polarized optical microscopy (POM) affirm the reduction of crystallinity in biopolymer electrolytes after doping with ionic liquid (IL). Thermal and photoelectrochemical studies further affirm that synthesized material is well stable above 200 °C and shows a wide electrochemical window of 3.91 V. The ionic transference number measurement (t ion) confirms the predominance of ionic charge carriers in the present system. An electric double-layer capacitor (EDLC) and a dye-sensitized solar cell (DSSC) were fabricated by using the highest conducting corn starch polymer electrolyte. The fabricated EDLC and DSSC delivered an average specific capacitance of 130 F/g and an efficiency of 1.73% in one sun condition, respectively.

Ionic Liquid‐Supported Single‐Sodium‐Ion‐Conducting Styrene‐Maleic Anhydride Copolymer for Energy Storage Devices

Wide‐ranging research has been done on ionic liquid (IL)‐incorporated conducting polymers in energy storage devices. Herein, by taking the reaction advantage of styrene maleic anhydride (SMA) copolymer with sodium hydroxide, a sodium ion having polymeric material as an electrolyte is synthesized. 1,8‐Diazabicyclo[5.4.0]undec‐7‐enium acetate (DBU acetate) is prepared as an IL and added to the prepared polymer electrolyte to increase the matrix flexibility, semisolid nature, and ionic mobility inside the matrix. This semisolid sodium ion‐based electrolyte shows conductivity in the order of 10−5 S cm−1 and an electrochemical stability window of 2.52 volts with >97% of ionic transference. It also shows the diffusivity constant in the order of 10−4 m2 s−1 and ionic mobility in the order of 10−3 m2 v−1 s−1 at 30 °C. The hydrogel matrix shows a correlated type of hopping with a power exponent <1 at 30 °C with low‐energy requirement of ionic transport, that is, 0.709 eV. A high amount of capacitance is associated with electrolyte that has an insignificant electrode contribution. On behalf of these findings, SMA‐IL‐based semisolid polymer electrolyte confirms its potential for application in sodium ion‐based energy storage systems.

Sulfonated poly(ether ether ketone)-Protic ionic Liquid-Based anhydrous Proton-Conducting composite polymer electrolyte membranes for High-Temperature fuel cell applications

A high-temperature polymer electrolyte membrane fuel cell (PEMFC) has enormous potential to produce clean energy with minimal environmental pollution along with high energy density and conversion efficiency. In the present work, anhydrous proton-conducting polymer electrolyte membranes for prospective high-temperature fuel cell application were successfully prepared using different protic ionic liquids (PILs) and sulfonated poly(ether ether ketone) (SPEEK). The protic ionic liquids (PILs), 2-hydroxyethylammonium formate, diethylmethyl ammonium triflate, 1-ethylimidazolium bis(trifluoromethylsulfonyl)imide, 1,2-dimethyl imidazolium bis(trifluoro methylsulfonyl)imide, and diethylmethylammonium methanesulfonate were selected based on their favorable physicochemical properties. The effect of the incorporation of the PIL on the structural, thermal, and electrical transport properties of the composite SPEEK polymer electrolyte membranes was studied. The prepared polymer electrolyte membranes (PEMs) were characterized using Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), X-ray diffractometry (XRD), and electrochemical impedance spectroscopy (EIS) techniques. FTIR results indicated an interaction between the PIL and the SPEEK, which resulted in homogeneous and flexible membranes. The DSC results confirmed good miscibility and elucidated plasticizing effect of the incorporated PIL on the SPEEK polymer matrix. All the PEMs showed good thermal stability and high-temperature anhydrous proton conductivity, achieving best proton conductivity, ≈8 × 10–3 S cm−1 at 120 °C and low activation energy ≈0.26 eV, making it suitable for prospective high-temperature PEMFC applications.

Experimental Investigations on Highly Conducting Solid Bio‐Polymer Electrolytes Based on Latex of Calotropis gigantea Plant

AbstractThe study has prepared highly conducting polymer electrolyte films using solution cast technique with poly(vinylidene fluoride‐co‐hexafluoropropylene) PVDF‐HFP, mixture of ethylene carbonate (EC), and propylene carbonate (PC) as plasticizer and latex of Calotropis gigantea (CGL) as an ionic source. In this study, four films are prepared using PVDF‐HFP:CGL in ratio 1:1 with the increasing concentration of EC+PC as 1, 2, 3, and 4 M named as 1:1:1, 1:1:2, 1:1:3, 1:1:4. The prepared polymer electrolyte is examined by polarized optical microscopy (POM), elemental dispersive X‐ray technique (EDX), and complex impedance spectroscopy. EDX and POM are studied for the surface morphology of all prepared samples and to investigate the porous nature of films. The enhancement in ionic conductivity occurs due to CGL and increasing amount of EC‐PC. Conductivity of highest composition (1:1:4) polymer electrolyte film is found to be ≈10−3 S cm−1. The optimized polymer electrolyte film is considered as a promising candidate for application in supercapacitors.

On the ionic conductivity and mechanical behavior of cellulose-based electrolytes: Applications for rechargeable batteries

Our paper presents two approaches that are potentially industrially scalable to prepare polymer electrolytes for the development of next-generation rechargeable batteries involving new atoms like Na, Zn or Mg: (1) gel polymer electrolytes, GPE, and (2) solid polymer electrolytes, SPE. Cellulose nanocrystals (CNC) are used with different surface functions, surface charge and concentrations as a functional component in both systems. Systematic testing of their ionic conductivity as well as their dynamic mechanical behavior, which is critical for creating mechanically durable systems, has been performed. Higher ionic conductivity reaching up to 2.60 ± 0.57 mS/cm was obtained for cellulose based GPE, which is more than double the ionic conductivity tested for non-renewable Celgard® 2400 (1.15 ± 0.06 mS/cm). Whereas cellulose based SPE showed an ionic conductivity of up to 2.34 ± 0.28 × 10−6 S/cm, and in both systems, tailoring the surface charge on CNC surfaces significantly influenced the counterion mobility thereby improving the ionic conductivity.

Construction and performance of PVDF-HFP-matrix comb-like gel copolymer electrolyte for high-performance quasi-solid-state lithium-metal batteries

Rechargeable lithium metal batteries (LMBs) have encountered bottlenecks in energy density, durability, and safety issues. Designing functional polymer electrolytes has been considered as an effective way to develop high-performance of LMBs. In this study, PVDF-HFP-matrix polymeric electrolytes blended with copolymer P(MMA-co-PEGMEMA) (PPxPy) via a simple one-pot free-radical polymerization are successfully designed and prepared. It has been found that the PPxPy electrolytes can construct different comb-like networks via systematically tuning monomer ratios. The tailored PP5P5 gel electrolyte exhibited high ionic conductivity of 0.74 × 10−3 S cm−1 at room temperature (RT), an enlarged electrochemical window up to 4.77 V, high lithium-ion transference number tLi+ of 0.65, and good mechanical property with Yang's modulus up to 131 MPa. Benefited from these good properties, the Li||LiFePO4 batteries assembled with PP5P5 gel electrolyte achieved an exceptional discharge capacity of 152 mAh g−1 with nearly 100 % Coulombic efficiency after 150 cycles at 1C. Furthermore, the Li|PP5P5|NCM811 cell exhibits excellent reversible specific capacity of 188 mAh g−1 at 0.1C. Consequently, it can be anticipated the as-prepared functional polymer structure to provide a reliable method for the preparation of polymer electrolytes in quasi-solid-state batteries with high-energy-density.

Initiator-free in-situ synthesized polymer electrolytes with high ionic conductivity for dendrite-free lithium metal batteries

In-situ preparation of polymer electrolytes (PEs) can enhance electrolyte/electrode interface contact and accommodate the current large-scale production line of lithium-ion batteries (LIBs). However, reactive initiators of in-situ PEs may lead to low capacity, increased impedance and poor cycling performance. Flammable and volatile monomers and plasticizers of in-situ PEs are potential safety risks for the batteries. Herein, we adopt lithium difluoro(oxalate)borate (LiDFOB)-initiated in-situ polymerization of solid-state non-volatile monomer 1,3,5-trioxane (TXE) to fabricate PEs (In-situ PTXE). Fluoroethylene carbonate (FEC) and methyl 2,2,2-trifluoroethyl carbonate (FEMC) with good fire retardance, high flash point, wide electrochemical window and high dielectric constant were introduced as plasticizers to improve ionic conductivity and flame retardant property of In-situ PTXE. Compared with previously reported in-situ PEs, In-situ PTXE exhibits distinct merits, including free of initiators, non-volatile precursors, high ionic conductivity of 3.76 × 10−3 S cm−1, high lithium-ion transference number of 0.76, wide electrochemical stability window (ESW) of 6.06 V, excellent electrolyte/electrode interface stability and effectively inhibition of Li dendrite growth on the lithium metal anode. The fabricated LiFePO4 (LFP)/Li batteries with In-situ PTXE achieve significantly boosted cycle stability (capacity retention rate of 90.4% after 560 cycles) and outstanding rate capability (discharge capacity of 111.7 mAh g−1 at 3C rate).

A Highly Salt-Soluble Ketone-Based All-Solid-State Polymer Electrolyte with Superior Performances for Lithium-Ion Batteries

Solid polymer electrolytes (SPEs) have great potential to be used in high-safety lithium-ion batteries (LIBs). However, it is still a significant challenge for SPEs to develop high ionic conductivity, high mechanical strength, and good interior interfacial compatibility. In this work, a ketone-based all-solid-state electrolyte (PAD) resulting from allyl acetoacetate (AAA), diacetone acrylamide (DAAM), and poly(ethylene glycol) diacrylate (PEGDA) was prepared by UV-inducing photopolymerization. The abundant ketone groups endow the prepared PAD all-solid-state electrolyte with strong dissociation of lithium salts and weak coordination interactions between ketone groups and Li+. Depending on the unique properties of the ketone groups in the electrolyte system, the prepared polymer electrolytes show a high lithium-ion transference number of 0.87 and a wide electrochemical window of 4.95 V. Furthermore, the PAD electrolyte also exhibits superior viscoelasticity, which is beneficial for good contact with electrodes. As a result, the assembled LFP/PAD/Li cells with PAD electrolytes show good cycle performance and rate performance. Concretely, the all-solid-state symmetric lithium cells with the PAD electrolyte can achieve stable lithium plating and stripping at 0.05 mA cm-2 for over 1000 h at 60 °C. This work highlights the advantages of ketone-based electrolyte as a polymer electrolyte and provides a design method for advanced polymer electrolytes applied in high-performance solid lithium batteries.

Effect of ionic liquids on the performance of dye-sensitized solar cells using poly(vinyl alcohol)/ polypyrrole based polymer electrolytes

ABSTRACT A novel quasi-solid-state polymer electrolyte was prepared using poly(vinyl alcohol)-polypyrrole, potassium iodide, iodine, and ethylene carbonate mixed with two types of ionic liquids, 1-methyl-3-propylimidazolium iodide (MPII) and 1-ethyl-3-methylimidazolium iodide (EMII). The prepared polymer electrolyte was structurally characterized by FTIR spectroscopy. The lowest degree of crystallinity and activation energy were found in the MPII-incorporated polymer electrolytes. Higher values of dislocation density and microstrain are obtained for ionic liquid-incorporated polymer electrolytes. The lowest value of series resistance was observed in MPII-based polymer electrolyte and thereby the conduction was increased. The average roughness of the MPII-based polymer electrolyte at 17.901 nm was strongly dependent on the influence of the MPII content. The dye-sensitized solar cells (DSSC) built with MPII-based polymer electrolytes have achieved the highest photo-conversion efficiency of 4.51% under 100mWcm−2 illumination.

Preparation and characterization of Li doped -Arabic Gum-PVA polymer electrolyte

A series of Arabic Gum (AG) biodegradable membranes were prepared by Solution Casting Technique. AG membrane is brittle in nature. In order to increase the flexibility and mechanical strength, Poly-Vinyl Alcohol (PVA) is added in different weight ratios. Out of the different AG: PVA polymer blends, a membrane having good flexibility was chosen for the present work. A new polymer electrolyte system for Lithium battery application was prepared by adding different wt.% of Lithium Nitrate (LiNO3) to the fixed AG-PVA polymer blend. X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), and AC impedance measurements have been used to assess the Li-ion transport mechanism involved in the current polymer electrolyte AG-PVA-LN. The complexation between the salt and polymer matrix was confirmed by FTIR analysis. The Arrhenius behaviour was observed in all synthesized electrolytes, and the sample with the highest conductivity had the lowest activation energy. The prepared polymer electrolyte membranes have been characterized using X-ray Diffraction Analysis to confirm the amorphous nature.

Design of proton conducting solid biopolymer blend electrolytes based on chitosan‐potato starch biopolymers: Deep approaches to structural and ion relaxation dynamics of H+ ion

AbstractThe need for flexible energy storage devices for advanced technologies has encouraged researchers to focus on environmental‐friendly biopolymers. In this work, chitosan (CS) and potato starch (PS) biopolymers are blended to prepare proton conducting solid electrolytes. Based on the X‐ray diffraction (XRD) inspection, the most amorphous blended film with the lowest crystallinity degree was selected to prepare polymer electrolytes. The variation in Fourier‐transform infrared spectroscopy (FTIR) bands were used to investigate the occurrence of interactions among the ammonium thiocyanate (NH4SCN) salt and CS:PS polymer blends. The experimental results of electrochemical impedance spectroscopy (EIS) were simulated with electrical equivalent circuit (EEC) modeling to determine the circuit elements. The highest value of S cm−1 was recorded for the sample included 40 wt.% of dopant salt. The dielectric analyses were helpful in separating the regions ascribed to electrode and molecular polarizations. The combination of circuit elements achieved from the EEC modeling and Koops phenomenological interpretation is used to understand the behavior of the loss tangent (tanδ) pattern. The AC conductivity pattern followed Jonscher's power law. The relaxation dynamics interrelated with ions is explained using electric modulus approaches. The peaks hidden in the dielectric loss () spectra, were manifested in the imaginary part of electric modulus () pattern. The ‐ patterns were used to shed light on the coupling between ionic motion and polymer chain dynamics.

Studies on structural, electrical and electrochemical properties of biodegradable PVP/starch blend polymer electrolytes with ammonium ceric nitrate for energy storage devices

As a new approach, biodegradable solid polymer blend polymer electrolytes are prepared using a synthetic polymer Poly [vinyl pyrrolidone] (PVP) and a biopolymer Starch with constant amount of Ammonium ceric nitrate. The Biopolymer starch is used to enhance the biodegradability of the polymer membranes. The polymer electrolytes are prepared by solution casting method using deionized water as solvent. The prepared electrolytes are analyzed with structural, vibrational, electrical and electrochemical behavior by using different characterization techniques. The amorphous nature of the blend polymer electrolytes has been confirmed by X-Ray diffraction (XRD) analysis. PVP/cassava starch/ammonium ceric nitrate polymer electrolyte shows high amorphous nature. In FTIR study, polymers-salt complexation and molecular vibrations are observed in the electrolytes. The ionic conductivity and dielectric measurement of the electrolytes are carried out by impedance spectroscopy. The maximum ionic conductivity of 8.1 × 10−6 S/cm is observed at room temperature for 80% PVP: 20% cassava starch: 2% ammonium ceric nitrate (ACN) system. The dielectric properties of the prepared polymer electrolytes are also analyzed. The electrolyte having higher ionic conductivity is tested with cyclic voltammetry (CV) and linear sweep voltammetry (LSV) studies that reveal the electrochemical properties and range of potential window of the polymer electrolyte.

Effect of ZnO nanoparticle content on the amorphousness of conducting jackfruit seed starch-PVA blend polymer electrolyte

Nanocomposite polymer electrolyte films based on a blend of two polymers jackfruit seed starch (JSS) and poly (vinyl alcohol) (PVA) complexed with nano-particle zinc oxide (ZnO) (i.e., (50 wt% JSS/50 wt% PVA) + x wt% ZnO where x = 0, 2, 4, 6, 8, 10, 12 and 14) were prepared by using the casting solution method. Electrochemical impedance spectroscopy (EIS) has been employed between the frequencies of 10 Hz and 1 MHz to get the optimum values of the conductivity of the prepared polymer electrolyte films. The effect of ZnO nano-filler concentration on the chemical bonding, crystallinity, morphology, and ionic conductivity has been studied. The maximum ionic conductivity at ambient temperature of 1.10 × 10–6 S cm−1 was obtained for (50 wt% JSS/50 wt% PVA) + 10 wt% ZnO JSS-PVA blend film and it is attributed to the highest amorphous content.

Optical and dielectric characterization of biopolymer pectin based electrolytes with NaCl

Biopolymer pectin based polymer electrolytes with sodium chloride (NaCl) were prepared by solution casting method. Semi crystalline nature of pectin is reduced to reach the amorphous nature by addition of NaCl salt,investigated by X-ray diffraction analysis and XRD deconvolution technique. Investigation of FTIR and FTIR deconvolution exposed the occurrence of complexation and increment of free ion by addition of NaCl. The shifting of UV absorbance band of pectin demonstrates the optical properties of the prepared polymer electrolytes. Optical bandgap of pectin polymer electrolyte was decreased from 3.13 eV to 2.98 eV due to the electrons transition from valence band to conduction band. The measurements of dielectric constants were conceded out on these films in the frequency range 42–106 Hz from 303K to 373 K. From all these characterisation, 3 wt.% of NaCl doped polymer-salt complex system performed well.

Preparation and characterization of proton (H+) conducting solid blend polymer electrolytes based on PEO/P(VdF-HFP) incorporated with NH4SCN

A new H+ ion-conducting solid blend polymer electrolytes system comprising of Poly (ethylene oxide) (PEO) and Poly (vinylidene fluoride-co-hexafluoropropylene) P(VdF-HFP) and ammonium thiocyanate (NH4SCN) have been prepared using solution casting technique. The X-Ray Diffraction (XRD) study demonstrates that there is a decrease in crystalline peaks of polymer electrolytes by increasing NH4SCN salt. FT-IR analysis confirms the interaction between polymers and salt. Using complex impedance spectroscopy, electrical characteristics have been determined with a 42Hz to 1MHz frequency range. The electrical conductivity varies with temperature and shows Arrhenius behaviour. The activation energy decreases as the salt content is increased. Frequency-dependent conductivity, dielectric permittivity (ε′) modulus (M′), and Loss tangent (tanδ) analysis of the prepared polymer electrolytes is also carried out. Argand plots are used to investigate the dynamics of ion relaxation. To analyze the electrochemical behaviour of the electrolytes, linear sweep voltametric (LSV) and cyclic voltametric (CV) measurements are performed. Thus, it is confirmed that the prepared polymer electrolytes are suitable for energy storage devices.

OPTICAL AND ELECTRIC MODULUS STUDIES OF PMMA: CH3COOLi COMPLEXES WITH THE ADDITION OF EMIMTFSI

Using solution casting technique PMMA with Lithium acetate of polymer electrolytes like PMMA (60 wt. %): CH3COOLi (40 wt. %): EMIMTFSI (0 wt. %, 0.5 wt. %, 1 wt. %) by incorporating ionic liquid are prepared. From UV-Visible studies maximum band gap (eV) is 2.8 eV for PMMA: CH3COOLi : EMIMTFSI (60:40:1 wt.%). Tangent dielectric loss revealed the behavior of the ion charge carrier’s polymer electrolyte system. Electric modulus studies revealed the information about charge carrier’s relaxation behavior. From the results, prepared polymer electrolyte films are the best candidates for energy storage devices

Design of non-faradaic EDLC from plasticized MC based polymer electrolyte with an energy density close to lead-acid batteries

The investigation of biodegradable polymer electrolyte for energy device applications is of great importance as a suitable alternative to the conventional electrolytes. This paper explores the employment of plasticized methylcellulose (MC)-based polymer electrolytes for energy storage EDLC device application with an energy density (46.29 Wh kg−1) close enough to lead-acid batteries. The results have shown that the inclusion of plasticizer can enhance the ionic conductivity to 1.17 × 10−3 S cm−1. It was found that the prepared polymer electrolyte was stable up to 2.1 V, which is sufficient to be employed as electrolyte and separator in fabrication of electrical double layer capacitor (EDLC). Both te and ti values have been quantified from the TNM measurements, where the ti values for the electrolytes containing 32 wt.% and 40 wt.% of glycerol plasticizer have been found as 0.963 and 0.802, respectively. The performance of the assembled EDLC was assessed using both cyclic voltammetry (CV) and charge-discharging responses. The absence of redox peaks is evidenced from the CV. The value of initial specific capacitance (Cspe) of the fabricated EDLC is 411.52 F g−1. The results achieved in this study can be considered as a breakthrough in EDLC devices.

Synthesis and Characterization of Proton Conducting Polymer Electrolytes based on Poly (N-vinyl pyrrolidone) and Polyvinylchloride

Poly (N-vinyl pyrrolidone) (PVP), Polyvinylchloride (PVC) blend membrane doped with different molar weight percentage of NH4Br has been prepared by solution casting technique using dimethyleformamide (DMF) as solvent and characterized for electrical properties. The prepared polymer electrolyte has been studied by XRD, FT-IR, Dielectric and Capacitance measurements. The XRD results show that the amorphous nature of PVP has increased in 70%PVP: 30%PVC. It is also observed that the amorphous nature of 70%PVP: 30%PVC is further increased by the addition of different concentration of NH4Br. A complex formation of PVP: PVC, PVP: PVC: NH4Br have been confirmed by FT-IR studies. Proton conductivity for the above film has been measured using impedance spectroscopy. The polymer blends 70%PVP: 30%PVC shows an ionic conductivity of 8.46X10-8 Scm-1. The conductivity of the blend film increases as concentration of NH4Br increases. The maximum proton conductivity 2.78X10-3 Scm-1 has been observed for 70%PVP: 30%PVC: 0.6 Molar weights (MWt) NH4Br. The primary proton battery with configuration of Zn + ZnSO4.7H2O/70PVP:30PVC: 0.6 Mwt% NH4Br/PbO2 + V2O5 are fabricated and tested.

Ultrathin polymer electrolyte film prepared by in situ polymerization for lithium metal batteries

Polymer materials demonstrate tremendous potential in constructing high-performance solid-state lithium metal batteries (LMBs). However, the polymer-based solid-state batteries assembled via the ex situ process generally exhibit poor electrolyte/electrode interfacial contact. Herein, we report an in situ solidification method based on ring-opening polymerization of ε-caprolactone (ε-CL), which enables an ultrathin film (11 μm) as solid polymer electrolytes (SPEs). Thanks to the mild reaction conditions and simple process, such SPEs are obtained efficiently and exhibit intimate interfacial contact with electrodes. It is worth noting that the initiator—stannous octoate—can react with the lithium metal anode to form a LiSn alloy layer, which possesses excellent lithium dendrite resistance. The addition of 15 wt% propylene carbonate leads to a semisolid-state battery with further improved ionic conductivity, which manifests outstanding cell performance at both 60 °C and room temperature. As a result, the semisolid-state LiFePO4/Li cell delivers a high discharge capacity of 150 mAh/g even after 100 cycles at room temperature, further highlighting the enhanced interfacial stability after the in situ solidification of ε-CL on the electrode surface. It is believed that such an in situ polymerization process to prepare polymer electrolytes has great potential for building the better solid-state LMBs.