Lithium Salts Research Articles

Ternary Solid Polymer Electrolytes at the Electrochemical Interface: A Computational Study.

Polymer-based solid-like gel electrolytes have emerged as a promising alternative to improve battery performance. However, there is a scarcity of studies on the behavior of these media at the electrochemical interface. In this work, we report classical MD simulations of ternary polymer electrolytes composed of poly(ethylene oxide), a lithium salt [lithium bis(trifluoromethanesulfonyl)imide], and different ionic liquids [1-butyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide and 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide] confined between two charged and uncharged graphene-like surfaces. The molecular solvation of Li+ ions and their diffusion as well as the polymer conformational picture were characterized in terms of the radial distribution functions, coordination numbers, number density profiles, orientations, displacement variance, polymer radius of gyration, and polymer end-to-end distance. Our results show that the layering behavior of the ternary electrolyte in the interfacial region leads to a decrease of Li+ mobility in the direction perpendicular to the electrodes and high energy barriers that hinder lithium cations from coming into direct contact with the graphene-like surface. The nature of the ionic liquid and its concentration were found to influence the structural and dynamic properties at the electrode/electrolyte interface, the electrolyte with low amounts of the pyrrolidinium-based ionic liquid being that with the best performance since it favors the migration of Li+ cations toward the negative electrode when compared to the imidazolium-based one.

Polyester-enhanced poly (cyclic carbonate-fluoride)-based polymer electrolyte for stable circulating solid lithium batteries

Polymer solid-state electrolytes have become one of the promising materials for constructing solid-state lithium batteries due to their excellent processability and good compatibility with electrode interfaces. However, their limited electrochemical performance and mechanical strength have hindered their widespread application. Through the adoption of an in-situ thermal curing method, we successfully prepared a poly(carbonate-fluoride) solid-state electrolyte, utilizing a polyester separator with abundant polar groups as a reinforcing framework. The introduction of ionic liquid into the solid polymer electrolyte not only enhances the mobility of polymer chain segments to improve ionic conductivity but also, in synergy with trifluoromethyl, promotes lithium salt dissociation while restricting the migration of lithium salt anions. Additionally, their reaction with the lithium metal anode generates the LiF-rich SEI, regulating the deposition of lithium dendrites. The resulting 31VPIF/OZ exhibited outstanding ionic conductivity (3.58 × 10−4 S cm−1 at 25 °C), Li-ion migration number (0.52), and electrochemical window (5.4 V). Li | 31VPIF/OZ | Li battery cycled for 1000 h at 0.1 mA cm−2 without short-circuiting. Importantly, Li | | LiFePO4 battery demonstrated a high capacity retention rate of 91.5 % after 600 cycles at 0.5C (25 °C). Thus, through the synergistic interplay of polymer structure design and fillers, we have successfully achieved stable cycling in solid-state lithium batteries, providing robust support for their application in rechargeable lithium battery technology.

High‐Performance All‐Solid‐State Lithium Metal Batteries Enabled by Ionic Covalent Organic Framework Composites

AbstractIonic covalent organic frameworks (iCOFs) are crystalline materials with stable porous structures. They hold great potential for ion transport, particularly as solid‐state electrolytes (SSEs) for all‐solid‐state lithium metal batteries (ASSLMBs). However, achieving an ionic conductivity of over 10−3 S cm−1 at room temperature using pure‐iCOF‐based SSEs, even adding additives such as lithium salts, is challenging as the voids work as strong resistances. Thus, highly conductive iCOFs typically require quasi‐solid‐state configurations with organic solvents or plasticizers. In this study, composites comprising iCOFs and poly(ionic liquid) (PIL) are prepared to make all‐solid‐state iCOFs electrolytes with an exceptional ionic conductivity up to 1.50 × 10−3 S cm−1 and a high Li+ transference number of > 0.80 at room temperature. Combined experimental and computational studies show that the co‐coordination and competitive coordination mechanism established between the PIL, lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), and iCOFs enabled rapid Li+ transport while restricting TFSI− movement. ASSLMB cells, made of composite SSEs and LiFePO4 composite cathode, demonstrate an initial discharge capacity of 141.5 mAh g−1 at 1C and r.t., with an impressive capacity retention of 87% up to 800 cycles. Overall, this work presents a breakthrough approach for developing advanced SSEs for next‐generation high‐energy‐density ASSLMBs.

Improvement of performance for flexible film dosimeter by incorporating additive agents

Objective. To evaluate the reduction in energy dependence and aging effect of the lithium salt of pentacosa−10,−12-diynoic acid (LiPCDA) films with additives including aluminum oxide (Al2O3), propyl gallate (PG), and disodium ethylenediaminetetracetate (EDTA). Approach. LiPCDA films exhibited energy dependence on kilovoltage (kV) and megavoltage (MV) photon energies and experienced deterioration over time. Evaluations were conducted with added Al2O3 and antioxidants to mitigate these issues, and films were produced with and without Al2O3 to assess energy dependence. The films were irradiated at doses of 0, 3, 6, and 12 cGy at photon energies of 75 kV, 105 kV, 6 MV, 10 MV, and 15 MV. For the energy range of 75 kV to 15 MV, the mean and standard deviation (std) were calculated and compared for the values normalized to the net optical density (netOD) at 6 MV, corresponding to identical dose levels. To evaluate the aging effect, PG and disodium EDTA were incorporated into the films: sample C with 1% PG, sample D with 2% PG, sample E with 0.62% disodium EDTA added to sample D, and sample F with 1.23% disodium EDTA added to sample D. Main results. Films containing Al2O3 demonstrated a maximum 15.8% increase in mean normalized values and a 15.1% reduction in std, reflecting a greater netOD reduction at kV than MV energies, which indicates less energy dependence in these films. When the OD of sample 1–4 depending on the addition of PG and disodium EDTA, was observed for 20 weeks, the transmission mode decreased by 8.7%, 8.3%, 29.3%, and 27.3%, respectively, while the reflection mode was 5.4%, 3.0%, 37.0%, and 34.5%, respectively. Significance. Al2O3 effectively reduced the voltage and MV energy dependence. PG was more effective than disodium EDTA in preventing the deterioration of film performance owing to the aging effect.

Lignin Derived Ultrathin All-Solid Polymer Electrolytes with 3D Single-Ion Nanofiber Ionic Bridge Framework for High Performance Lithium Batteries.

The lignin derived ultrathin all-solid composite polymer electrolyte (CPE) with a thickness of only 13.2µm, which possess 3D nanofiber ionic bridge networks composed of single-ion lignin-based lithium salt (L-Li) and poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) as the framework, and poly(ethylene oxide)/lithium bis(trifluoromethanesulfonyl)imide (PEO/LiTFSI) as the filler, is obtained through electrospinning/spraying and hot-pressing. t. The Li-symmetric cell assembled with the CPE can stably cycle more than 6000h under 0.5mA cm-2 with little Li dendrites growth. Moreover, the assembled Li||CPE||LiFePO4 cells can stably cycle over 700 cycles at 0.2 C with a super high initial discharge capacity of 158.5 mAh g-1 at room temperature, and a favorable capacity of 123 mAh g-1 at -20°C for 250 cycles. The excellent electrochemical performance is mainly attributed to the reason that the nanofiber ionic bridge network can afford uniformly dispersed single-ion L-Li through electrospinning, which synergizes with the LiTFSI well dispersed in PEO to form abundant and efficient 3D Li+ transfer channels. The ultrathin CPE induces uniform deposition of Li+ at the interface, and effectively inhibit the lithium dendrites. This work provides a promising strategy to achieve ultrathin biobased electrolytes for solid-state lithium ion batteries.

Anti‐Selective Carbosilylation: Nickel‐Catalyzed Multicomponent Reaction of Solid Me3SiZnI

AbstractThe stereodefined and highly substituted vinylsilanes are essential building blocks for constructing complex organic molecules. Transition metal‐mediated silylmetalation of alkynes was developed to overcome the limitations of conventional hydrosilylations; however, a very limited study was carried out to utilize transient vinylmetal species in cross‐coupling reactions. Moreover, they produce syn‐adduct, and the anti‐selective cross‐coupling is still unknown and highly desired. Silylzinc reagents are highly functional group tolerant, however, their synthesis from pyrophoric silyllithium and dissolved lithium salts hampers cross‐coupling reactions. Our novel solid silylzinc reagents circumvent these constraints are employed in the anti‐selective synthesis of vinylsilanes via a multi‐component reaction involving Me3SiZnI, terminal alkynes, and activated alkyl halides. An intensive computational and experimental investigation of the mechanism reveals an equilibrium between the intermediate syn‐ and anti‐adducts; the greater barrier at the single electron reduction of alkyl halides and the thermodynamic stability of the Ni(III) adduct determine the anti‐selectivity.

In Situ Polymerization Facilitating Practical High-Safety Quasi-Solid-State Batteries.

Quasi-solid-state batteries (QSSBs) are gaining widespread attention as a promising solution to improve battery safety performance. However, the safety improvement and the underlying mechanisms of QSSBs remain elusive. Herein, a novel strategy combining high-safety ethylene carbonate-free liquid electrolyte and in situ polymerization technique is proposed to prepare practical QSSBs. The Ah-level QSSBs with LiNi0.83Co0.11Mn0.06O2 cathode and graphite-silicon anode demonstrate significantly improved safety features without sacrificing electrochemical performance. As evidenced by accelerating rate calorimetry tests, the QSSBs exhibit increased self-heating temperature and onset temperature (T2), and decreased temperature rise rate during thermal runaway (TR). The T2 has a maximum increase of 48.4°C compared to the conventional liquid batteries. Moreover, the QSSBs do not undergo TR until 180°C (even 200°C) during the hot-box tests, presenting significant improvement compared to the liquid batteries that run into TR at 130°C. Systematic investigations show that the in situ formed polymer skeleton effectively mitigates the exothermic reactions between lithium salts and lithiated anode, retards the oxygen release from cathode, and inhibits crosstalk reactions between cathode and anode at elevated temperatures. The findings offer an innovative solution for practical high-safety QSSBs and open up a new sight for building safer high-energy-density batteries.

High voltage electrochemical performance of single crystal LiNi0.8Co0.1Mn0.1O2 cathode materials with Al-Mg dual doping

Single-crystal materials have high structural stability and low parasitic side reactions for nickel-rich cathodes due to the absence of grain boundaries. However, they suffer challenges such as the complex synthesis route, sluggish lithium-ion diffusion kinetics, and microcracking evolution at high voltage. Bulk co-doping of Al and Mg into the precursors is first employed by a co-precipitation method, and then the Al-Mg dual-doped single-crystal NCM811 cathode is successfully prepared using a straightforward one-step method to reduce production cost. The cycle retention of the corresponding optimized single-crystal material is notably increased by 24.36% compared to the commercial counterpart at 1 C and a high voltage of 4.5 V. Additionally, the discharge capacity at 0.1 C is improved by 4.64% compared to the commercial one with an appropriate annealing temperature and lithium salt ratio. Some advances in the synthesis approach and modification strategy for developing commercial single-crystal material are provided.

Slow sustained releasing LiNO3 from graphite electrode reservoir to regulate solvation structure and stabilize interface

The high de-solvation energy derived from the solvent-rich Li+ solvation sheath and the resultant porous organic-rich electrode/electrolyte interface has hindered the commercialization of low-concentration electrolytes (LCEs). Here, unlike the common method so far reported, we invent an approach of sustained releasing LiNO3 from the graphite (Gr) anode reservoir to optimize the solvation structure and form a stable interface in LCEs. The solubility limit can be overcome by introducing LiNO3 directly in the Gr slurry. Moreover, the stronger binding energy between NO3– and Li+ drives NO3– enter the Li+ solvation sheath, weakening the shielding effect of solvent on Li+, and surprisingly increasing the coordination of PF6- to Li+. Thermodynamically, the corresponding lowest unoccupied molecular orbital energy levels of anions decrease, reducing the de-solvation energy of Li+ and forming a Li3N&LiF-rich solid electrolyte interface (SEI). This inorganic-rich SEI demonstrates advantages of inhibiting the decomposition of solvent and facilitating the transmission of Li+. As a result, the cell with Gr anode containing 1 wt% LiNO3 exhibits superior cycle performance in LCE, almost no degradation within 200 cycles, even higher than that in conventional concentration electrolyte. More importantly, the continuous consumption of NO3– in turn promotes its sustained redissolution from the anode, constituting a virtuous circle of regulating solvation structure, stabilizing interface and improving battery performance. This work blazes a new trail to revive lithium salt additives with low solubility, and expands the design strategy and application prospect of LCEs by building the bridges between regulating the solvation structure and constructing favorable electrode/electrolyte interface.

Engineering Ion Conduction Nanodomain Spacing and Interface Environment for Ultrastable All‐Solid‐State Lithium Metal Batteries

AbstractBlock copolymer electrolytes are of great interest due to the combination merits of ion conduction and mechanical strength. However, there lacks a comprehensive understanding on the role of nanodomain spacing in ion‐dipole coordinating environment and interface environment. Herein, the lithium salts with varied binding energy are chosen to tune nanodomain spacing in Polyether‐block‐Polyamide (PEO‐PA) polymer. Spectra characterizations in combination with molecular dynamic simulations systematically demonstrate adding LiFSI salts with lower binding energy contributes to forming larger PEO nanodomain spacing and clarifies the relationship between nanodomain spacing and ion‐dipole coordinating environment as well as interface environment. The larger PEO nanodomain spacing in LiFSI doping PEO‐PA electrolytes (AEOF) creates a loosely Li+‐EO group coordinating environment and improves pristine interface contact. In addition, the formation of solid‐electrolyte interphase rich in LiF and Li3N enhances interfacial stability. Therefore, the ionic conductivity of AEOF electrolytes is significantly improved. Furthermore, the Li||AEOF||Li cells exhibit extraordinary cycling life over 10000 h (416 days) at 0.1 mA cm−2 with a capacity of 0.1 mAh cm−2. This study provides a new insight into the ion‐dipole coordinating environment and interface environment, which benefits the theory‐guided design of all‐solid‐state polymer electrolytes.

Sulfur-containing soft Lewis base polymers for improved lithium-ion conductivity under polymer-in-salt conditions

Abstract Solid polymer electrolytes have been intensively studied to improve the safety and energy density of lithium-ion batteries (LiBs). Although high-rate performance of LiBs has been reported in electrolytes under polymer-in-salt conditions with an excess of lithium salts and polymers, effective conditions for achieving high ionic conductivity remain unresolved. In this study, we elucidate the mechanism and high Li-ion transportability of poly(sulfone-thioether) under polymer-in-salt conditions. In particular, the composition of the polymer with an asymmetric Li salt, lithium(fluorosulfonyl)(trifluoromethane sulfonyl)imide (LiFTFSI), induced a high ionic conductivity above 10−5 S/cm, which is higher than that of the poly(ethylene oxide) (PEO)-Li salt system. Under polymer-in-salt conditions, the enhanced conductivity of poly(sulfone-thioether) contrasts with the conductivity drop observed in the conventional PEO system. These results show the superiority of polymers with soft Lewis bases, such as sulfur donor atoms, for Li-ion transport under polymer-in-salt conditions.

Using tea waste to produce a high-performance lithium-ion capacitor—Bio-graphite/ Li4Ti5O12 (LTO)

Lithium-Ion Capacitors (LICs) show promise as electrochemical energy storage devices (EESDs) that combine a supercapacitor-type cathode and a Lithium Ion-type anode with an organic electrolyte containing lithium salts. In this study, porous carbon (LICs cathode) was synthesized from tea waste biomass using a potassium carbonate (K2CO3) activator. During synthesis, the weight ratios for carbon and activator were 1:2 (GAC-2); 1:3 (GAC-3); and, 1:4 (GAC-4), respectively. Meanwhile, the synthesis of Li4Ti5O12 material (LICs anode) was carried out using a salt-assisted solid-state method. Based on X-ray diffraction patterns (XRD), the synthesized carbon material initially showed an amorphous structure (without activator), which was followed by the formation of graphite peaks (activator addition). The XRD pattern of prepared LTO material matched the cubic spinel structure of Li4Ti5O12 (Fd-3m, PDF no. 49–0207). Scanning electron microscope (SEM) analysis revealed macropores in the synthesized carbon material in all samples whereas the LTO material displayed a cubic morphology with a smooth surface. The specific discharge capacity of the prepared LTO was 160 mAh/g (half-cell vs. Li). The Specific Discharge Capacities of Lithium ion capacitor (LIC) of LTO/HC, LTO/GAC-2, LTO/GAC-3, and LTO/GAC-4 samples were 22, 36, 42 and 51 mAh/g, respectively. The Cyclic voltammetry verified that the prepared cells have stable pseudocapacity properties. The prepared LIB from tea waste bio-graphite/LTO shows its high-performance characteristic indicates from its energy density, power density and lifetime.

Stabilization of the Interface between a PEO-Based Lithium Solid Polymer Electrolyte and a 4-Volt Class Cathode, LiCoO2, by the Addition of LiPF6 as a Lithium Salt

Stabilization of the Interface between a PEO-Based Lithium Solid Polymer Electrolyte and a 4-Volt Class Cathode, LiCoO2, by the Addition of LiPF6 as a Lithium Salt

In situ polymerization design of a quasi-solid electrolyte enhanced by NMP additive for lithium metal batteries

Solid polymer electrolytes (SPEs) are considered one promising candidate for lithium metal batteries due to their high flexibility, low cost, and roll-to-roll scalability. However, conventional SPEs prepared via ex situ methods are confronted with challenges such as poor contact and high resistance at the electrode|SPE interface, as well as low ionic conductivity at room temperature. In this study, we developed a quasi-solid electrolyte (QSE) using an in situ polymerization approach, employing butyl acrylate as the monomer and incorporating NMP as an additive. Spectroscopic investigations and DFT calculations revealed that NMP tends to form an overleaf-structured [Li(NMP)3][TFSI] complex with LiTFSI, promoting lithium salt dissociation. Owing to this advantage, the QSE exhibits high room-temperature ionic conductivity (6.94 × 10−4 S cm−1) and an extensive electrochemical stability window (5.01 V vs. Li+/Li). Furthermore, the in situ polymerization method facilitates full contact at the interface, enhancing the interfacial stability and reducing the interface resistance, thus resulting in stable cycling of Li|Built-in QSE|Li symmetric cell for 1100 h at 0.1 mA cm−2. The assembled LiFePO4|Built-in QSE|Li cell also demonstrates excellent rate and long-term cycling performance. Our findings offer valuable insights into the interaction between organic additives and lithium salts and present a novel strategy for the development of polymer electrolytes.

Unveiling the effect law of carbon dots with polyfunctional groups on interface structure and ion migration in polymer electrolytes for solid lithium battery

Solid polymer electrolyte (SPE) has been considered as promising candidate electrolyte for solid-state lithium metal battery. However, the low ion conductivity and poor interface stability seriously hinder the development of SPE. Introducing the functional filler is a commonly used and effective approach to solving these issues. The poor compatibility and ambiguous mechanism of action are currently the main challenges. In this study, we design and synthesize carbon dots (NSFCDs) with quaternary functional groups, which are introduced into the SPE in the polymerization process of hybrid polymer electrolyte (HPE). The detailed effect law of polyfunctional groups on the polymer chain structure, interface structure of electrolyte/electrode and ion migration is systematically revealed. The dense polymer network endows HPE with enhanced mechanical properties. Through the regulation of polymer segments, the coordination environment of lithium ions is altered, promoting ion transport. The solid electrolyte interface (SEI) induced by NSFCDs and lithium salt anions effectively improves the morphology of lithium ion deposition and alleviates volume strain. As a result, the HPE based on polyethylene oxide (PEO) constructed by free radical polymerization of NSFCDs and polyethylene glycol diacrylate (PEGDA) exhibits excellent comprehensive performance, the assembled Li symmetric battery can cycle stably for 4000 h.

Synthetic Studies and Structural Aspects of Dinuclear Sulfur Titanium Compounds

AbstractA series of dinuclear sulfur‐bridged titanium derivatives [Ti(η5‐C5Me5)R(μ‐S)]2 (R=NMe2 (1), Ph (2), CH2Ph (3), CH2SiMe3 (4)) has been synthesized from the reaction of [Ti(η5‐C5Me5)Cl(μ‐S)]2 with the corresponding lithium salt or Grignard reagent. Formulation of 1–4 as symmetric dimers has been confirmed by crystallographic studies. The analogous reaction with Mg(C3H5)Cl afforded the paramagnetic mixed‐valence Ti(III)/Ti(IV) compound [{Ti(η5‐C5Me5)(μ‐S)}2(μ‐C3H5)] (5). Contrasting with complexes 1–4, compound 5 exhibits a bridging μ‐CH2CHCH2 fragment between the titanium atoms, which prevents the formation of a planar Ti2S2 core in the solid‐state structure. Complex 1 reacts with SiH3Ph to give [{Ti(η5‐C5Me5)(μ‐S)}2(μ‐NMe2)] (6), a paramagnetic mixed‐valence Ti(III)/Ti(IV) compound, structurally and electronically similar to 5. Under mild conditions, treatment of compounds 3 and 4 with H2 (1 atm) generates quantitatively the Ti(III) tetrametallic sulfide cluster [Ti(η5‐C5Me5)(μ3‐S)]4, along with the corresponding alkane.

Synthesis and Properties of the LiMn2O4 Cathode Material for Lithium-ion Batteries

Spinel LiMn2O4 was synthesized by high-temperature solid-state method with lithium salt and manganese salt as raw materials, which were mixing with anhydrous ethanol as solvent under stirring, and calcining at high temperature in in the oxygen atmosphere. X-ray diffraction (XRD) and scanning electron microscope (SEM) showed that the size of lithium manganese particles with spinel structure was 80 to 200 nm, and the particle size distribution was uniform. The results showed that the prepared LiMn2O4 sample sintered at 700°C exhibited superior electrochemical performance when used as a cathode material for lithium-ion batteries with a voltage window of 2.5–4.8 V. The first charge-discharge specific capacity and first discharge capacity can reach 158.0 mAh‧g-1 and 138.4 mAh‧g-1, respectively, at 0.1 A‧g-1 current density, and the first Coulomb retention efficiency is 87.6%. The discharge specific capacity of the LiMn2O4 material can be maintained at 114 mAh‧g-1 when the test current density was returned to 0.1 A‧g-1 after 60 cycles.

A Healable Quasi-Solid Polymer Electrolyte with Balanced Toughness and Ionic Conductivity.

Solid polymer electrolytes (SPEs) have garnered extensive attention as potential alternatives to traditional liquid electrolytes, primarily due to their prowess in curbing lithium dendrite formation and preventing electrolyte leaks. The quest for SPEs that are both mechanically robust and exhibit superior ionic conductivity has been vigorous. However, achieving a harmonious balance between these two attributes remains a significant challenge. In this study, we introduce a novel quasi-solid electrolyte, ingeniously crafted from a poly(urethane-urea) network, enriched with lithium salts and plasticizers. This innovative composition not only boasts remarkable toughness but also ensures commendable ionic conductivity. Our post-gelation method yields gel polymer electrolytes that undergo rigorous evaluation, leading to an optimized version that stands out with its exceptional room-temperature ionic conductivity (2.94×10-4 S cm-1) and outstanding toughness (11.9 MJ m-3). Moreover, it demonstrates a broad electrochemical window (4.73 V), remarkable stability across a 600-hour cycle test, a high capacity retention exceeding 80 % after 100 cycles at 0.2 C, and a noteworthy self-healing capability. This quasi-solid polymer electrolyte emerges as a promising contender to replace current liquid electrolyte solutions.

An Ultrathin Solid Electrolyte for High‐Energy Lithium Metal Batteries

AbstractSolid‐state electrolytes (SSEs) are key to unlocking the potential of lithium metal batteries (LMBs), but their high thickness (>100 µm) due to poor mechanical properties limits energy density improvements. Herein, an ultrathin (≈5 µm) polymer SSE with a high Young's modulus (10.6 GPa), made from a polyvinylidene fluoride‐hexafluoropropylene (PVDF‐HFP) matrix and an ethylene diamine tetraacetic acid (EDTA) additive is proposed. By virtue of the electron‐donating property, EDTA induces the conformation transformation of PVDF‐HFP, enhancing the mechanical strength by a fine‐grain strengthening mechanism. In addition, PVDF‐HFP with cis‐conformation shortens the pathway for Li+, promotes the Li+ dissociation and immobilizes the anions of lithium salt, thus increasing the ionic conductivity (2.47 × 10−4 S cm−1) and transfer number (0.59) of the electrolyte. Moreover, the electrolyte also possesses a wide voltage window (4.7 V) and good heat/flame resistance. The half cells and full cells with the electrolytes show good cycling and rate performance. Notably, a pouch cell based on the electrolyte exhibits impressive energy densities of 516 Wh kg−1 and 1520 Wh L−1 (excluding packages), showing great potential for practical use in LMBs.

An autonomous self-healing mechanism to improve the chemical durability vs. moisture of PVDF-based gel electrolytes for lithium-ion batteries

Lithium-ion batteries (LIBs) are at the forefront of electrochemical energy storage both for consumer electronics, and for power/energy more demanding applications, such as in automotive and grid levelling. However, their chemical and electrochemical stability must be further improved. Among the instability causes, a major role is played by residual moisture. As a matter of fact, hydrofluoric acid generated by hydrolysis of LiPF6, the most common lithium salt in LIBs, causes safety issues and performance losses. Here we demonstrate the scavenging properties vs. HF of a barium silicate glass used as a filler in a PVDF-HFP based gel polymer electrolyte. A full LiTi2(PO4)3|electrolyte|LiMn2O4 cell is stable for 200 cycles at 0.1C.