Search Results (11)

Solid polymer electrolytes (SPEs) have garnered significant attention due to their potential in all-solid-state batteries (ASSBs). However, adoption remains constrained by challenges such as low thermal stability and limited ionic conductivity. Here, we report on an electrospun (PAN/PEO)- conductive salt (LiBF₄) system, where the influence of varying polyacrylonitrile (PAN) and polyethylene oxide (PEO) ratios, along with different plasticizer concentrations, is evaluated. Notably, the 50:50 PAN/PEO sample exhibited the highest ionic conductivity, reaching 1∙10⁻² S/cm at 55 °C. This system also balanced conductivity and processability. Succinonitrile (SN) significantly influenced the morphology and conductivity. Samples with increased SN content showed enhanced capacity in symmetrical cells, achieving ~140 mAs/cm² for an 18:9:1 polymer (PAN/PEO):SN:conductive salt (LiBF₄) composition. The enhanced lithium-ion conductivity of the electrospun blend is attributed to the deliberate use of an unmixable PAN–PEO system. Their immiscibility creates well-defined interfacial regions within fibers, acting as efficient lithium-ion pathways. These findings support electrospun polymer blends as promising candidates for high-performance SPEs for ASSB development. Full article

Solid-state batteries (SSBs) have been widely studied as next-generation lithium-ion batteries (LiBs) for many electronic devices due to their high energy density, stability, nonflammability, and chemical stability compared to LiBs which consist of liquid electrolytes. However, solid electrolytes exhibit poor electrochemical characteristics due to their interfacial properties, and the sintering process, which necessitates high temperatures, is an obstacle to the commercialization of SSBs. Hence, the aim of this study was to improve the interfacial properties of the lithium tantalum phosphate (LTPO) solid electrolyte by adding succinonitrile (SN) on the interface of the LTPO particle to enhance ionic conductivity without the sintering process. Electrochemical impedance spectroscopy (EIS), the Li symmetric cell test, and the galvanostatic cycle test were performed to verify the performance of the SN-containing LTPO composite electrolyte. The LTPO composite solid electrolyte exhibited a high ionic conductivity of 1.93 × 10⁻⁴ S/cm at room temperature (RT) compared to the conventional LTPO. Also, it showed good cycle stability, and low interfacial resistance with Li metal, ensuring electrochemical stability. On the basis of our experimental results, the performance of solid electrolytes could be improved by adding SN and lithium salt. In addition, the SN can be used to fabricate the solid electrolytes without the sintering process at high temperatures. Full article

A new approach to developing structural sodium batteries capable of operating in ambient-temperature conditions has been successfully achieved. The developed multifunctional structural electrolyte (SE) using poly(ethylene oxide) (PEO) as a matrix integrated with succinonitrile (SN) plasticizers and glass-fiber (GF) reinforcements identified as GF_PEO-SN-NaClO₄ showed a tensile strength of 32.1 MPa and an ionic conductivity of 1.01 × 10⁻⁴ S cm⁻¹ at room temperature. It displayed a wide electrochemical stability window of 0 to 4.9 V and a high sodium-ion transference number of 0.51 at room temperature. The structural electrode (CF|SE) was fabricated by pressing the structural electrolyte with carbon fibers (CFs), and it showed a tensile strength of 72.3 MPa. The fabricated structural battery half-cell (CF||SE||Na) demonstrated good cycling stability and an energy density of 14.2 Wh kg⁻¹, and it retained 80% capacity at the end of the 200th cycle. The cycled electrodes were observed using scanning electron microscopy, which revealed small dendrite formation and dense albeit uniform deposition of the sodium metal, helping to avoid a short-circuit of the cell and providing more cycling stability. The developed multifunctional matrix composites demonstrate promising potential for developing ambient-temperature sodium structural batteries. Full article

Solid-state lithium metal batteries (LMBs) have been extensively investigated owing to their safer and higher energy density. In this work, we prepared a novel elastic solid-state polymer electrolyte based on an in situ-formed elastomer polymer matrix with ion-conductive plasticizer crystal embedded with Li_6.5La₃Zr_1.5Ta_0.5O₁₂ (LLZTO) nanoparticles, denoted as LZT/SN-SPE. The unique structure of LZT/SN-SPE shows excellent elasticity and flexibility, good electrochemical oxidation tolerance, high ionic conductivity, and high Li⁺ transference number. The role of LLZTO filler in suppressing the side reactions between succinonitrile (SN) and the lithium metal anode and propelling the Li⁺ diffusion kinetics can be affirmed. The Li symmetric cells with LZT/SN-SPE cycled stably over 1100 h under a current density of 5 mA cm⁻², and Li||LiFePO₄ cells realized an excellent rate (92.40 mAh g⁻¹ at 5 C) and long-term cycling performance (98.6% retention after 420 cycles at 1 C). Hence, it can provide a promising strategy for achieving high energy density solid-state LMBs. Full article

A PMMA-based gel polymer electrolyte (GPE) modified by a plastic crystal succinonitrile (SN) was synthesized using a facile solvent-casting method. The effects of SN additives upon lithium-ion dissociation and ionic conductivity were investigated primarily using Fourier transform infrared spectroscopy and electrochemical impedance spectroscopy, accompanied by other structural characterization methods. The results show that SN is distributed uniformly in the PMMA matrix with a high content and produces vast dipoles that benefit the dissociation of lithium salt. Hence, the SN-modified GPE (SN-GPE) achieves an excellent ionic conductivity of 2.02 mS·cm⁻¹ and good mechanical properties. The quasi-solid-state ECD fabricated using the SN-GPE exhibits stable cyclability and excellent electrochromic performance, in which the bleaching/coloration response time is 10 s/30 s. These results add significant insight into understanding the inter- and intra-molecular interaction in SN-GPEs and provide a type of practicable high-performance GPE material for solid electrochromic devices. Full article

An all-solid–state dye-sensitized solar cell is one of the non-fossil fuel-based electrochemical devices for electricity generation in a high-temperature region. This device utilizes a redox mediator, which is a fast ion-conducting solid polymer electrolyte (SPE). The SPE makes the device economical, thinner, and safer in high-temperature regions. The SPE generally has a form of matrix−plasticizer−redox salts. Succinonitrile (SN) is generally employed as a plasticizer for reducing the crystallinity of poly(ethylene oxide), abbreviated as PEO, a common polymeric matrix. In the present paper, the structural and thermal properties of tetramethyl succinonitrile (TMSN) were compared with SN for its application as a solid plasticizer. TMSN and SN both are plastic crystals. TMSN has four methyl groups by replacing the hydrogen of the SN, resulting in higher molecular weight, solid–solid phase transition temperature, and melting temperature. We thoroughly studied the structural, thermal, and electrical properties of the [(1−x)PEO: xTMSN] blend for utilizing it as a matrix, where x = 0–0.25 in mole fraction. The FT-IR spectra and XRD patterns of the blends exhibited PEO-alike up to x = 0.15 mole and TMSN-alike for x > 0.15 mole. Differential scanning calorimetry revealed formation of a eutectic phase from x = 0.1 mole and phase separation from x = 0.15 mole. The blends with x = 0.1–0.15 mole had a low value of PEO crystallinity. Thermogravimetric analysis showed thermal stability of the blends up to 75 °C. The blends exhibited electrical conductivity, σ_25°C more than 10⁻⁹ S cm⁻¹, and Arrhenius behavior (activation energy, ~0.8 eV) in a temperature region, 25–50 °C. Full article

The solar cell has been considered one of the safest modes for electricity generation. In a dye-sensitized solar cell, a commonly used iodide/triiodide redox mediator inhibits back-electron transfer reactions, regenerates dyes, and reduces triiodide into iodide. The use of iodide/triiodide redox, however, imposes several problems and hence needs to be replaced by alternative redox. This paper reports the first Co²⁺/Co³⁺ solid redox mediators, prepared using [(1−x)succinonitrile: xPEO] as a matrix and LiTFSI, Co(bpy)₃(TFSI)₂, and Co(bpy)₃(TFSI)₃ as sources of ions. The electrolytes are referred to as SN_E (x = 0), Blend 1_E (x = 0.5 with the ethereal oxygen of the PEO-to-lithium ion molar ratio (EO/Li⁺) of 113), Blend 2_E (x = 0.5; EO/Li⁺ = 226), and PEO_E (x = 1; EO/Li⁺ = 226), which achieved electrical conductivity of 2.1 × 10⁻³, 4.3 × 10⁻⁴, 7.2 × 10⁻⁴, and 9.7 × 10⁻⁷ S cm⁻¹, respectively at 25 °C. Only the blend-based polymer electrolytes exhibited the Vogel-Tamman-Fulcher-type behavior (vitreous nature) with a required low pseudo-activation energy (0.05 eV), thermal stability up to 125 °C, and transparency in UV-A, visible, and near-infrared regions. FT-IR spectroscopy demonstrated the interaction between salt and matrix in the following order: SN_E < Blend 2_E < Blend 1_E << PEO_E. The results were compared with those of acetonitrile-based liquid electrolyte, ACN_E. Full article

Solid-state plastic crystal electrolytes (SPCEs) have attracted much attention due to their high ionic conductivity at room temperature and polymer-like plasticity. Herein, we made a LiFePO₄||Li solid state battery based on SPCEs. A SPCE film is made up of glass fiber, succinonitrile (SN), lithium bis (triflu-romethanesulphonyl) imid (LiTFSI), and LiNO₃. Glass fiber is introduced to improve the mechanical property, and LiNO₃ served as an additive to stabilize electrolyte/Li interface. The SPCE film delivers a high ionic conductivity of 7.3 × 10⁻⁴ S cm⁻¹ at room temperature and has excellent stability with Li-metal anode. SPCE is also infused into cathode electrode and used as the interface with cathode particles, which can access a large interface contact area and deform reversibly with volume change. The LiFePO₄||Li solid state battery based on SPCE can work well at ambient temperature, which shows a high initial specific capacity of 121.4 mAh g⁻¹ and has 86.9% retention after 90 cycles at 0.5 C. Full article

We report a new process technique for electrode manufacturing for all solid-state batteries. Porous electrodes are manufactured by a tape casting process and subsequently infiltrated by a plastic crystal polymer electrolyte (PCPE). With a following isostatic lamination process, the PCPE was further integrated deeply into the porous electrode layer, forming a composite electrode. The PCPE comprises the plastic crystal succinonitrile (SN), lithium conductive salt LiTFSI and polyacrylonitrile (PAN) and exhibits suitable thermal, rheological (ƞ = 0.6 Pa s @ 80 °C 1 s⁻¹) and electrochemical properties (σ > 10⁻⁴ S/cm @ 45 °C). We detected a lowered porosity of infiltrated and laminated electrodes through Hg porosimetry, showing a reduction from 25.6% to 2.6% (NCM infiltrated to laminated) and 32.9% to 4.0% (LTO infiltrated to laminated). Infiltration of PCPE into the electrodes was further verified by FESEM images and EDS mapping of sulfur content of the conductive salt. Cycling tests of full cells with NCM and LTO electrodes with PCPE separator at 45 °C showed up to 165 mAh/g at 0.03C over 20 cycles, which is about 97% of the total usable LTO capacity with a coulomb efficiency of between 98 and 99%. Cycling tests at 0.1C showed a capacity of ~128 mAh/g after 40 cycles. The C-rate of 0.2C showed a mean capacity of 127 mAh/g. In summary, we could manufacture full cells using a plastic crystal polymer electrolyte suitable for NCM and LTO active material, which is easily to be integrated into porous electrodes and which is being able to be used in future cell concepts like bipolar stacked cells. Full article

In the present work, the effect of temperature and additives on the ionic conductivity of mixed organic/ionic liquid electrolytes (MOILEs) was investigated by conducting galvanostatic charge/discharge and ionic conductivity experiments. The mixed electrolyte is based on the ionic liquid (IL) (EMI/TFSI/LiTFSI) and organic solvents EC/DMC (1:1 v/v). The effect of electrolyte type on the electrochemical performance of a LiCoO₂ cathode and a SnO₂/C composite anode in lithium anode (or cathode) half-cells was also investigated. The results demonstrated that the addition of 5 wt.% succinonitrile (SN) resulted in enhanced ionic conductivity of a 60% EMI-TFSI 40% EC/DMC MOILE from ~14 mS·cm⁻¹ to ~26 mS·cm⁻¹ at room temperature. Additionally, at a temperature of 100 °C, an increase in ionic conductivity from ~38 to ~69 mS·cm⁻¹ was observed for the MOILE with 5 wt% SN. The improvement in the ionic conductivity is attributed to the high polarity of SN and its ability to dissolve various types of salts such as LiTFSI. The galvanostatic charge/discharge results showed that the LiCoO₂ cathode with the MOILE (without SN) exhibited a 39% specific capacity loss at the 50th cycle while the LiCoO₂ cathode in the MOILE with 5 wt.% SN showed a decrease in specific capacity of only 14%. The addition of 5 wt.% SN to the MOILE with a SnO₂/C composite-fiber anode resulted in improved cycling performance and rate capability of the SnO₂/C composite-membrane anode in lithium anode half-cells. Based on the results reported in this work, a new avenue and promising outcome for the future use of MOILEs with SN in lithium-ion batteries (LIBs) can be opened. Full article

Considering the safety issues of Li ion batteries, an all-solid-state polymer electrolyte has been one of the promising solutions. Achieving a Li ion conductivity of a solid-state electrolyte comparable to that of a liquid electrolyte (>1 mS/cm) is particularly challenging. Even with characteristic ion conductivity, employment of a polyethylene oxide (PEO) solid electrolyte has not been sufficient due to high crystallinity. In this study, hybrid solid electrolyte (HSE) systems have been designed with Li_1.3Al_0.3Ti_0.7(PO₄)₃ (LATP), PEO and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI). A hybrid solid cathode (HSC) is also designed using LATP, PEO and lithium cobalt oxide (LiCoO₂, LCO)—lithium manganese oxide (LiMn₂O₄, LMO). The designed HSE system has 2.0 × 10⁻⁴ S/cm (23 °C) and 1.6 × 10⁻³ S/cm (55 °C) with a 6.0 V electrochemical stability without an additional separator membrane introduction. In these systems, succinonitrile (SN) has been incorporated as a plasticizer to reduce crystallinity of PEO for practical all-solid Li battery system development. The designed HSC/HSE/Li metal cell in this study operates without any leakage and short-circuits even under the broken cell condition. The designed HSC/HSE/Li metal cell in this study displays an initial charge capacity of 82/62 mAh/g (23 °C) and 123.4/102.7 mAh/g (55 °C). The developed system overcomes typical disadvantages of internal resistance induced by Ti ion reduction. This study contributes to a new technology development of all-solid-state Li battery for commercial product design. Full article