Effect of additives in PEO/PAA/PMAA composite solid polymer electrolytes on the ionic conductivity and Li ion battery performance

Polyethylene oxide (PEO) based-solid polymer electrolytes were prepared with low weight polymers bearing carboxylic acid groups added onto the polymer backbone, and the variation of the conductivity and performance of the resulting Li ion battery system was examined. The composite solid polymer electrolytes (CSPEs) were composed of PEO, LiClO_4, PAA (polyacrylic acid), PMAA (polymethacrylic acid), and Al₂O₃. The addition of additives to the PEO matrix enhanced the ionic conductivities of the electrolyte. The composite electrolyte composed of PEO:LiClO₄:PAA/PMAA/Li_0.3 exhibited a low polarization resistance of 881.5 ohms in its impedance spectra, while the PEO:LiClO₄ film showed a high value of 4,592 ohms. The highest ionic conductivity of 9.87 × 10⁻⁴ S cm⁻¹ was attained for the electrolyte composed of PEO:LiClO₄:PAA/PMAA/Li_0.3 at 20 °C. The cyclic voltammogram of Li⁺ recorded for the cell consisting of the PEO:LiClO₄:PAA/PMAA/Li_0.3:Al₂O₃ composite electrolyte exhibited the same diffusion process as that obtained with an ultra-microelectrode. Based on this electrolyte, the applicability of the solid polymer electrolytes to lithium batteries was examined for an Li/SPE/LiNi_0.5Co_0.5O₂ cell.     

Te doping effect on the structure and ionic conductivity of LiTa2PO8 solid electrolyte

LiTa₂PO₈ (LTPO) is a new solid-state electrolyte material, which has high bulk ionic conductivity and low grain boundary ion conductivity. However, the conductivity of materials synthesized by conventional methods is much lower than the theoretically calculated values. In this work, large radius Te ion are doped at Ta (3)-site in order to enlarge the lattice parameters and increase Li content, which are beneficial for increasing ionic conductivity. The Te substitution changes the Ta surrounding environment, increases the binding capacity of Ta–O, and reduces the attraction of oxygen to lithium ions in the system. The prepared dense Li_1.04Ta_1.96Te_0.04PO₈ ceramic electrolyte exhibits a low activation energy of 0.193 eV and four times higher ion conductivity (4.5 × 10^?4 S cm^?1) than undoped samples. Moreover, Li_1.04Ta_1.96Te_0.04PO₈ shows a stable cycling performance in the symmetric Li/Li cells and the Li/CPE/Li_1.04Ta_1.96Te_0.04PO₈/LiFePO₄ batteries with the separation of a thin PEO membrane.     

Controllable Li3PS4–Li4SnS4 solid electrolytes with affordable conductor and high conductivity for solid-state battery

High ionic conductivity, low grain boundary impedance, and stable electrochemical property have become the focus for all-solid-state lithium–sulfur batteries (ASSLSB). One of the approaches is to promote the rapid diffusion of lithium ions by regulating the chemical bond interactions within the framework. The structure control of P⁵⁺ substitution for Sn⁴⁺ on lithium-ion transport was explored for a series of Li₃PS₄–Li₄SnS₄ glass–ceramic electrolytes. Results showed that the grain boundary impedance of the glass electrolyte was reduced after heat treatments. The formation of LiSnPS microcrystals, a good superionic conductor, was detected by X-ray diffraction tests. Electrochemical experiments obtained the highest conductivity of 29.5 S cm⁻¹ at 100°C and stable electrochemical window from –0.1 to 5 V at 25°C. In addition, the cell battery was assembled with prepared electrolyte, which is promoted as a candidate solid electrolyte material with improved performance for ASSLSB.     

Rapid preparation and performances of garnet electrolyte with sintering aids for solid-state Li–S battery

Lithium-sulfur (Li–S) batteries are attractive due to their high theoretical energy density. However, conventional Li–S batteries with liquid electrolytes undergo polysulfide shuttle-effect and lithium dendrite formation during charge/discharge process, leading to poor electrochemical performance and safety issues. Garnet type Li₇La₃Zr₂O₁₂ (LLZO) solid-state electrolyte (SSE) restricts the penetration of polysulfides and exhibits high ionic conductivity at room temperature (RT). Herein, Li_6.5La₃Zr_1.5Nb_0.5O₁₂ (LLZNO) ceramic electrolyte using Li₃PO₄ (LPO) as sintering aids (LLZNO-LPO) is prepared by the rapid sintering method and is applied to construct a shuttle-effect free solid-state Li–S battery. The SSE displays high conductive pure cubic-LLZO phase; during the rapid sintering, LPO melts and junctions the voids between the grains, thus improves Li⁺ conductivity. As a result, the LLZNO-LPO ceramic electrolyte with Li⁺ conductivity of 4.3 × 10^?4 S cm^?1 and high critical current density (CCD) of 1.2 mA cm^?2 is obtained at RT. The Li–S solid-state battery which utilizes LLZNO-LPO ceramic electrolyte can deliver an initial discharge capacity of 943 mA h·g^?1 and 602 mA h·g^?1 retention after 60 cycles. In the same time, the initial coulombic efficiency is as high as 99.5%, indicating that the SSE can effectively block the polysulfide shuttle towards the Li anode and fulfill a shuttle-free Li–S battery.     

Phase evolution,structure, and electrochemical performance of Al-, Ga- and Ta- substituted Li7La3Zr2O12 ceramic electrolytes by a modified wet chemical route

Garnet-type Li₇La₃Zr₂O₁₂ (LLZO) is one of the most promising solid-state electrolytes (SSEs) for advanced solid-state lithium batteries (SSLBs). In this work, Li_6.25Al_0.25La₃Zr₂O₁₂, Li_6.4Ga_0.2La₃Zr₂O₁₂, and Li_6.4La₃Zr_1.4Ta_0.6O₁₂ ceramics are prepared by a modified wet chemical route. The composition of the black mixtures derived from the precursors is ascertained. The phase evolution and structural properties from the ceramic mother powders to the final ceramic electrolytes are discussed in detail. The characteristic of cubic LLZO with the space group I-43d arises in the Li_6.4Ga_0.2La₃Zr₂O₁₂ ceramic electrolyte pellet after the secondary higher-temperature (1200 °C) sintering. The Rietveld refinement reveals the roles of Al³⁺ substitution at the Li⁺ sites and Ta⁵⁺ substitution at the Zr⁴⁺ sites to adjust crystal structure. In addition, the electrochemical performance of the ceramic pellets is also investigated. Remarkably, the Li_6.4La₃Zr_1.4Ta_0.6O₁₂ ceramic electrolyte has the most outstanding electrochemical performance, showing the high ionic conductivity of 6.88 × 10^?4 S cm^?1 (25 °C), the low activation energy of 0.42 eV and an extremely low electronic conductivity of 1.77 × 10^?8 S cm^?1 (25 °C). Overall, it is supposed that this work may help to achieve high-quality modified LLZO ceramic electrolytes, especially using the wet chemical strategy.     

Investigating the effect of interaction behavior on the ionic conductivity of Polyester/LiClO4 blend systems

We describe the interaction behavior between Polyester and Li⁺ that affects the ionic conductivity on binary electrolyte of lithium perchlorate (LiClO₄) blends with Poly(ethylene adipate), (PEA); Poly(1,4-butylene adipate), (PBA); Poly(1,6- hexamethylene adipate), (PHA); and Polycarprolatone (PCL), respectively. The individual four binary blend systems are similar and fully miscible, a different ionic conductivity exists in the binary Polyester electrolyte system corresponds to the result of the different interactions strength between lithium perchlorate (LiClO₄) and various Polyesters. The lithium ion is able to coordinate with more functional groups of PEA polymer chain than that in other three polyester chains. Both DSC and FTIR studies demonstrate that the ability of PEA to donate its electron to coordinate with Li⁺ is significantly stronger than that of PBA, PHA and PCL. Consequently, the maximum ionic conductivity (1.06 × 10^?5 S cm^?1) at ambient temperature (30 °C) occurred at a composition of PEA/LiClO₄ (90/10).It is further found that the ionic conductivity of Polyester electrolyte is not only dependent on the electron donation strength of carbonyl group, but also on the molecular structure of Polyester.     

Boosting lithium-ion transport capability of LAGP/PPO composite solid electrolyte via component regulation from ‘Ceramics-in-Polymer’ to ‘Polymer-in-Ceramics'

The design and regulation of the ion transport channels in the polymer electrolyte is an important means to improve the lithium ion transport behavior of the electrolyte. In this work, we for the first time combined the high ionic conductive inorganic ceramic electrolyte Li_1.5Al_0.5Ge_1.5(PO₄)₃ (LAGP) with flexible polypropylene oxide (PPO) polymer electrolyte to synthesize a high-filling LAGP/PPO composite solid electrolyte film and regulated the ion transport channels from ‘Ceramics-in-Polymer’ mode to ‘Polymer-in-Ceramics' mode by optimizing the ratio of LAGP vs. PPO. The results reveal that when the LAGP content <40%, the electrolyte belongs to ‘LAGP-in-PPO’, and then changes to ‘PPO-in-LAGP’ when the LAGP content exceeds 40%. Compared with ‘LAGP-in-PPO’, the ‘PPO-in-LAGP’ shows better comprehensive properties, especially for the 75% LAGP-filled PPO electrolyte, the room-temperature ionic conductivity is as high as 3.46 × 10^?4 Scm^?1, the ion migration number and voltage stable window reach 0.83 and 4.78 V respectively. This high-filled composite electrolyte possesses high tensile stress of 40 MPa with a strain of 46% and withstands working environment up to 200 °C. The NCM622/Li solid-state battery composed of this electrolyte also presents good rate and cycle performances with a capacity retention of 80% after 230 cycles at 0.3C because of its high ion transport capability and good inhibition of lithium dendrites. This composite structural design is expected to develop high-performance solid-state electrolytes suitable for high-voltage solid-state lithium batteries.     

Synthesis of Ga-doped Li7La3Zr2O12 solid electrolyte with high Li+ ion conductivity

Garnet-type Li₇La₃Zr₂O₁₂ (LLZO) Li⁺ ion solid electrolyte is a promising candidate for next generation high-safety solid-state batteries. Ga-doped LLZO exhibits excellent Li⁺ ion conductivity, higher than 1 × 10^?3 S cm^?1. In this research, the doping amount of Ga, the calcination temperature of Ga-LLZO primary powders, the sintering conditions and the evolution of grains are explored to demonstrate the optimum parameters to obtain a highly conductive ceramics reproducibly via conventional solid-state reaction methods under ambient air sintering atmosphere. Cubic LLZO phase is obtained for Li_6.4Ga_0.2La₃Zr₂O₁₂ powder calcined at low temperature 850 °C. In addition, ceramic pellets sintered at 1100 °C for 320 min using this powder have relative densities higher than 94% and conductivities higher than 1.2 × 10^?3 S cm^?1 at 25 °C.     

Novel PEO-based solid composite polymer electrolytes with inorganic–organic hybrid polyphosphazene microspheres as fillers

Novel solid-state composite polymer electrolytes based on poly (ethylene oxide) (PEO) by using LiClO₄ as doping salts and inorganic–organic hybrid poly (cyclotriphosphazene-co-4,4′-sulfonyldiphenol) (PZS) microspheres as fillers were prepared. Electrochemical and thermal properties of PEO-based polymer electrolytes incorporated with PZS microspheres were studied. Differential scanning calorimetry (DSC) results showed there was a decrease in the glass transition temperature of the electrolytes and the crystallinity of the samples in the presence of the fillers. Maximum ionic conductivity values of 1.2 × 10⁻⁵ S cm⁻¹ at ambient temperature and 7.5 × 10⁻⁴ S cm⁻¹ at 80° were obtained and lithium ion transference number was 0.29. Compared with traditional ceramic fillers such as SiO₂, the addition of PZS microspheres increased the ionic conductivity of the electrolytes slightly and led to remarkable enhancement in the lithium ion transference number.     

Influence of dry- and wet-milled LLZTO particles on the sintered pellets

A Ta-doped Li₇La₃Zr₂O₁₂ (LLZTO) solid electrolyte is a promising candidate for all-solid-state lithium battery due to its high ionic conductivity and stability against lithium metal. In this work, physicochemical properties of both dry- and wet-milled LLZTO particles were investigated. Based on X-ray diffraction, Fourier transform–infrared, thermogravimetric analysis, and scanning electron microscopy results, it was confirmed that highly reactive LLZTO powder prepared in dry milling conditions exhibited faster size reduction, rougher surface morphology, fewer surface impurities, and less agglomerated particles, in contrast to those in wet milling conditions. Sintering these dry-milled powders at 1320°C for 10 min in the air via solid-state reaction produced dense ceramic pellets with a relative density of 97.4%. The room-temperature ionic conductivity for LLZTO pellet via the dry milling was determined to be 6.94 × 10⁻⁴ S cm⁻¹. Li–sulfur batteries based on the pellets showed an initial discharge capacity of 1301 mA h g⁻¹ and a coulombic efficiency of 99.82% when cycled at room temperature. The effect of the milled powder on the sintered pellets was discussed in terms of boundary mobility, pore mobility, and morphology.     

Composite polymer electrolyte incorporating WO3 nanofillers with enhanced performance for dendrite-free solid-state lithium battery

All solid-state lithium batteries (ASS-LBs) with polymer-based solid electrolytes are a prospective contender for the next-generation batteries because of their high energy density, flexibility, and safety. Among all-polymer electrolytes, PEO-based solid polymer electrolytes received huge consideration as they can dissolve various Li salts. However, the development of an ideal PEO-based solid polymer electrolyte is hindered by its insufficient tensile strength and lower ionic conductivity due to its semi-crystalline and soft chain structure. In order to lower the crystallization and improve the performance of PEO-based solid polymer electrolyte, tungsten trioxide (WO₃) nanofillers were introduced into PEO matrix. Herein, a PEO₂₀/LiTFSI/x-WO₃ (PELI-xW) (x = 0%, 2.5%, 5%, 10%) solid composite polymer electrolyte was prepared by the tape casting method. The solid composite polymer electrolyte containing 5 wt% WO₃ nanofillers achieved the highest ionic conductivity of 7.4 × 10^-4 S cm^-1 at 60 °C. It also confirms a higher Li-ion transference number of 0.42, good electrochemical stability of 4.3V, and higher tensile strength than a PEO/LiTFSI (PELI-0W) fillers-free electrolyte. Meanwhile, the LiFePO₄│PELI-xW│Li ASS-LBs demonstrated high performance and cyclability. Based on these findings, it can be considered a feasible strategy for the construction of efficient and flexible PEO-based solid polymer electrolytes for next-generation solid-state batteries.     

Efficiently enhance the proton conductivity of YSZ-based electrolyte for low temperature solid oxide fuel cell

Yttrium stabilized zirconia (YSZ) as a typical oxygen ionic conductor has been widely used as the electrolyte for solid oxide fuel cell (SOFC) at the temperature higher than 1000 °C, but its poor ionic conductivity at lower temperature (500–800 °C) limits SOFC commercialization. Compared with oxide ionic transport, protons conduction are more transportable at low temperatures due to lower activation energy, which delivered enormous potential in the low-temperature SOFC application. In order to increase the proton conductivity of YSZ-based electrolyte, we introduced semiconductor ZnO into YSZ electrolyte layer to construct heterointerface between semiconductor and ionic conductor. Study results revealed that the heterointerface between ZnO and YSZ provided a large number of oxygen vacancies. When the mass ratio of YSZ to ZnO was 5:5, the fuel cell achieved the best performance. The maximum power density (P_max) of this fuel cell achieved 721 mW cm^?2 at 550 °C, whereas the P_max of the fuel cell with pure YSZ electrolyte was only 290 mW cm^?2. Further investigation revealed that this composite electrolyte possessed poor O^2? conductivity but good proton conductivity of 0.047 S cm^?1 at 550 °C. The ionic conduction activation energy of 5YSZ-5ZnO composite in fuel cell atmosphere was only 0.62 eV. This work provides an alternative way to improve the ionic conductivity of YSZ-based electrolytes at low operating temperatures.     

Preparation of polymer electrolytes based on the polymerized imidazolium ionic liquid and their applications in lithium batteries

The polymer electrolytes based on a polymerized ionic liquid (PIL) as polymer host and containing 1,2‐dimethyl‐3‐butylimidazolium bis(trifluoromethanesulfonyl)imide (BMMIM‐TFSI) ionic liquid, lithium TFSI salt, and nanosilica are prepared. The PIL electrolyte presents a high ionic conductivity, and it is 1.07 × 10^?3 S cm^?1 at 60°C, when the BMMIM‐TFSI content reaches 60% (the weight ratio of BMMIM‐TFSI/PIL). Furthermore, the electrolyte exhibits wide electrochemical stability window and good lithium stripping/plating performance. Preliminary battery tests show that Li/LiFePO₄ cells with the PIL electrolytes are capable to deliver above 146 mAh g^?1 at 60°C with very good capacity retention. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40928.     

Composite polymer electrolytes based on electrospun thermoplastic polyurethane membrane and polyethylene oxide for all‐solid‐state lithium batteries

To improve the electrochemical properties and enhance the mechanical strength of solid polymer electrolytes, series of composite polymer electrolytes (CPEs) were fabricated with hybrids of thermoplastic polyurethane (TPU) electrospun membrane, polyethylene oxide (PEO), SiO₂ nanoparticles and lithium bis(trifluoromethane)sulfonamide (LiTFSI). The structure and properties of the CPEs were confirmed by SEM, XRD, DSC, TGA, electrochemical impedance spectroscopy and linear sweep voltammetry. The TPU electrospun membrane as the skeleton can improve the mechanical properties of the CPEs. In addition, SiO₂ particles can suppress the crystallization of PEO. The results show that the TPU‐electrospun‐membrane‐supported PEO electrolyte with 5 wt% SiO₂ and 20 wt% LiTFSI (TPU/PEO‐5%SiO₂‐20%Li) presents an ionic conductivity of 6.1 × 10^?4 S cm^?1 at 60 °C with a high tensile strength of 25.6 MPa. The battery using TPU/PEO‐5%SiO₂‐20%Li as solid electrolyte and LiFePO₄ as cathode shows an attractive discharge capacity of 152, 150, 121, 75, 55 and 26 mA h g^?1 at C‐rates of 0.2C, 0.5C, 1C, 2C, 3C and 5C, respectively. The discharge capacity of the cell remains 110 mA h g^?1 after 100 cycles at 1C at 60 °C (with a capacity retention of 91%). All the results indicate that this CPE can be applied to all‐solid‐state rechargeable lithium batteries. © 2018 Society of Chemical Industry     

Electrochemical investigation of Li–Al anodes in oligo(ethylene glycol) dimethyl ether/LiPF<Subscript>6</Subscript>

1 M LiPF₆ dissolved in oligo(ethylene glycol) dimethyl ether with a molecular weight 500 g mol⁻¹ was investigated as a new electrolyte (OEGDME500, 1 M LiPF₆) for metal deposition and battery applications. At 25 °C a conductivity of 0.48 × 10⁻³ S cm⁻¹ was obtained and at 85 °C, 3.78 × 10⁻³ S cm⁻¹. The apparent activation barrier for ionic transport was evaluated to be 30.7 kJ mol⁻¹. OEGDME500, 1 M LiPF₆ allows operating temperature above 100 °C with very attractive conductivity. The electrolyte shows excellent performance at negative and positive potentials. With this investigation, we report experimental results obtained with aluminum electrodes using this electrolyte. At low current densities lithium ion reduction and re-oxidation can be achieved on aluminum electrodes at potentials about 280 mV more positive than on lithium electrodes. In situ X-ray diffraction measurements collected during electrochemical lithium deposition on aluminum electrodes show that the shift to positive potentials is due to the negative Gibbs free energy change of the Li–Al alloy formation reaction.     

Synthesis and sodium ionic conductivity for perovskite-structured Na0.25La0.25NbO3 ceramic

In this work, a perovskite-structured sodium ion conductor, Na_0.25La_0.25NbO₃ (NLNO) was developed from analogous Li_0.25La_0.25NbO₃ ceramic. NLNO ceramic was successfully synthesized by solid state reaction. The sodium ionic conduction in Na_0.25La_0.25NbO₃ ceramic was studied and the effect of sintering temperature on the microstructure, phase structure, density and sodium ionic conductivity for Na_0.25La_0.25NbO₃ was also discussed. Single phase of perovskite was successfully obtained from NLNO sintered at 1200 °C and 1250 °C, and the result shows high sintering temperature leads to a large grain size, large lattice parameters and high density. With an increase of sintering temperature from 1150 °C to 1250 °C, the conductivity of samples increases gradually. NLNO sintered at 1250 °C presents a high sodium ionic conductivity of 1.06 × 10^?5 S cm^?1 at 30 °C, which is much higher than that of electronic conductivity in NLNO sintered at 1250 °C.     

Chemically Modified Polyvinyl Butyral Polymer Membrane as a Gel Electrolyte for Lithium Ion Battery Applications

A novel porous membrane of chemically modified polyvinyl butyral (mPVB), with improved thermal properties and chemical stability for lithium ion battery applications, is successfully synthesized by utilizing the chain extension reaction of the OH units from PVB. The porous mPVB membranes are obtained via the tape casting and phase inversion method. The corresponding gel polymer electrolyte (GPE) is achieved by immersing the as‐prepared membranes in the liquid electrolyte. The electrochemical performances of the GPE show that the mPVB membranes have the features of good uniformity, high porosity ( ≈ 90%), great thermal stability, and high mechanical strength. Moreover, the GPE exhibits good chemical stability, a wide electrochemical window, as well as high ionic conductivity ( ≈ 1.21 × 10^?3 S cm^?1). A test of a Li/GPE/LiFePO₄ battery cell shows a capacity of 147.7 mAh g^?1 and excellent cycling stability, demonstrating the great potential of the mPVB‐based GPE for lithium ion battery applications.     

Processing of high-performance Co doped Y2O3 as a single-phase electrolyte for low temperature solid oxide fuel cell (LT-SOFC)

The high-performance single-phase semiconductor materials with higher ionic conductivity have drawn substantial attention in fuel cell applications. Semiconductor materials play a key role to enhance ionic conductivity subsequently promoting low temperature solid oxide fuel cell (LT-SOFC) research. Herein, we proposed a semiconductor Co doped Y₂O₃ (YCO) samples with different molar ratios, which may easily access the high ionic conductivity and electrochemical performances at low operating temperatures. The resulting fabricated fuel cell 10% Co doped Y₂O₃ (YCO-10) device exhibits high ionic conductivity of ∼0.16 S cm⁻¹ and a feasible peak power density of 856 mW cm⁻² along with 1.09 OCV at 530 °C under H₂/air conditions. The electrochemical impedance spectroscopy (EIS) reveals that YCO-10 electrolyte based SOFC device delivers the least ohmic resistance of 0.11–0.16 Ω cm² at 530-450 °C. Electrode polarization resistance of the constructed fuel cell device noticed from 0.59 Ω cm² to 0.28 Ω cm² in H₂/air environment at different elevated temperatures (450 °C to 530 °C). This work suggests that YCO-10 can be a promising alternative electrolyte, owing to its high fuel cell performance and enhanced ionic conductivity for LT-SOFC.     

Low temperature densification by lithium co-doping and its effect on ionic conductivity of samarium doped ceria electrolyte

Low temperature densification and improving the ionic conductivity of doped ceria electrolyte is important for the realization of efficient intermediate temperature solid oxide fuel cell system. Herein, we report the effect of lithium co-doping (1, 3, 5 and 7?mol%) in 20?mol% samarium doped ceria on the low temperature sinterability and conductivity. The synthesized nanoparticles by citrate-nitrate combustion method showed a decrease in lattice parameter and increase in oxygen vacancy with lithium content after calcination due to the substitution of Li⁺ into CeO₂ lattice. Upon sintering at 900?°C, the density improved and reached a maximum value of 98.6% for 5% Li which exhibited a dense microstructure than at 7% Li. 5%Li co-doping exhibited the best conductivity of 3.65?×?10^?04–1.81?×?10^?3 S?cm^?1 in the operative temperature range of IT-SOFC (550–700?°C).Our results demonstrate the significance of lithium as co-dopant for efficient low temperature sintering as well as improving the electrolyte conductivity.     

Effect of zwitterionic salt on the electrochemical properties of a solid polymer electrolyte with high temperature stability for lithium ion batteries

In this study, we prepare a kind of solid polymer electrolyte (SPE) based on N-ethyl-N′-methyl imidazolium tetrafluoroborate (EMIBF₄), LiBF₄ and poly(vinylidene difluoride-co-hexafluoropropylene) [P(VdF-HFP)] copolymer. The resultant SPE displays high thermal stability above 300 °C and high room temperature ionic conductivity near to 10⁻³ S cm⁻¹. Its electrochemical properties are improved with incorporation of a zwitterionic salt 1-(1-methyl-3-imidazolium)propane-3-sulfonate (MIm3S). When the SPE contains 1.0 wt% of the MIm3S, it has a high ionic conductivity of 1.57 × 10⁻³ S cm⁻¹ at room temperature, the maximum lithium ions transference number of 0.36 and the minimum apparent activation energy for ions transportation of 30.9 kJ mol⁻¹. The charge-discharge performance of a Li₄Ti₅O₁₂/SPE/LiCoO₂ cell indicates the potential application of the as-prepared SPE in lithium ion batteries.