Cross-linked Polymer Electrolyte Research Articles

Controllable In situ Polymerization of 1,3‐Dioxolane via Sustained‐Release Effect for Solid‐State Lithium Metal Batteries

AbstractIn situ formed poly(1,3‐dioxolane) (PDOL) electrolytes are of great interest due to the facile process and the improved interface contact. However, the practical application of in situ PDOL electrolytes is still plagued by fast solidification time (liquid state) and poor high‐voltage stability (solid state). Herein, the slow‐release carriers triglycidyl isocyanurate (TGIC), which play dual roles as initiator sustained‐release and network confinement, can tune DOL curing time and cathode/electrolyte interface chemistry is demonstrated. Specifically, the electronegative C≐O and epoxy groups in TGIC have an affinity with BF3, the decomposition product of lithium bis(oxalate)borate (LiDFOB), delaying BF3 protonation reaction and thus extending DOL solidification time. In addition, the epoxy groups in TGIC serve as crosslinking sites to form in situ crosslinked polymer electrolytes (TPDOL@FEC). The corresponding network structure suppresses the contact reaction between high‐fluidity organic components and cathodes, generating a uniform and thin cathode electrolyte interface layer. As a result, the TPDOL@FEC precursor solution can remain its liquid state even after resting 24 h at room temperature. The assembled LiNi0.6Co0.2Mn0.2O2||TPDOL@FEC||Li cells display an impressive capacity retention of 91.5% after 100 cycles at 4.4 V (0.5 C). This study is expected to be a leap in the pursuit of practically feasible in situ formed PDOL electrolytes.

Dynamically reversible cross-linked polymer electrolytes with highly ionic conductivity for dendrite-free lithium metal batteries

High-safety PEO-based electrolytes have attracted widespread attention, but their inefficient conduction of Li ions and poor contact with electrode interfaces deteriorate the performances of rechargeable lithium metal batteries. Herein, we design a vitrimer polymer electrolyte (V-SPE-PEG) with abundant dynamic imine bonds via Schiff base reaction between aldehyde and ammonia, which achieves high ionic conductivity and good interfacial compatibility with lithium anode. The dynamic polymer network in V-SPE-PEG exhibits solid-state plasticity because reversible imine bonding reactions enable the integrity of the polymer network to be maintained while altering the cross-linked points under external stimuli. Therefore, this 3D dynamic cross-linked network effectively facilitates the polymer chain dynamics and meanwhile enhances ionic conductivity. Additionally, dynamic bond exchange fosters electrolyte flowability and self-healing during lithium deposition, promoting a tightly integrated electrode/electrolyte interface while inhibiting lithium dendrites growth. Consequently, lithium symmetric cells utilizing the V-SPE-PEG electrolyte demonstrate exceptional long-term cycling stability, surpassing 1100 h and exhibit outstanding ionic conductivity of 2.7 × 10−4 S cm−1 at 30 °C. The LiFePO4||Li battery maintains stable cycling performance at both 40 °C and 60 °C. This study introduces an innovative approach to designing solid-state electrolytes for lithium-metal batteries.

UV cross-linked highly stable polymer garnet composite electrolyte with improved interphase for lithium metal batteries

The next-generation electric vehicles heavily rely on high-energy–density lithium metal batteries with enhanced safety. Replacing liquid electrolytes with solid-state polymer electrolytes offers superior protection, high flexibility, and stability. However, inadequate ionic conductivity and poor compatibility at the interfaces with the electrodes hinder the practical application of solid-state electrolytes. In this work, we developed a polyethylene glycol-based, highly cross-linked polymer electrolyte with a garnet-type, fast Li+ conductive Li6.2Al0.24La3Zr2O12 (Al-LLZO) filler. The Al-LLZO filler was incorporated into a cross-linking functional polymeric matrix of polyethylene glycol diacrylate, pentaerythritol tetrakis (3-mercaptopropionate), and lithium perchlorate salt. The cross-linked polymer garnet composite electrolyte (CPGCE) was prepared via UV-induced photo-polymerization. The resulting CPGCE exhibits superior free-standing flexibility, a desired ionic conductivity of 4.4 × 10−4 S cm−1, and a wide potential window up to 4.2 V. The Li|CPGCE|Li symmetric cell underwent stripping and plating at varying current densities of 0.05 to 0.3 mA cm−2, displaying a low overpotential range from ±0.02 V to ±0.08 V over 500 cycles. Similarly, the as-cycled Li|CPGCE|Li showed excellent stripping and plating performance at 0.1 mA cm−2 for 500 cycles at 60 °C. The incorporation of the Al-LLZO nanofiller provided active sites with continuous Li+ conducting pathways, suppressing the growth of dead lithium dendrites. The Li|CPGCE|LiFePO₄ full cell exhibited a discharge capacity of 155 mAh g−1 at a rate of 0.1C, with a coulombic efficiency of 96 % over 50 cycles at 25 °C. This work offers a straightforward and convenient approach to creating highly durable polymer composite electrolytes with enhanced interfacial stability, advancing the implementation of all-solid-state lithium metal batteries.

Three-dimensional cross-linked network deep eutectic gel polymer electrolyte with the self-healing ability enable by hydrogen bonds and dynamic disulfide bonds

Solid polymer electrolytes (SPEs) are effective solutions for the development of high-performance and flexible lithium metal batteries (LMBs). However, the key problems of SPEs including low ionic conductivity and inability to repair damage have hindered their industrialization process. In this work, a three-dimensional (3D) cross-linked network gel polymer electrolyte (CNGPE) is designed. The addition of deep eutectic solvent (DES) improves the ionic conductivity of CNGPE. The hydrogen bonds and dynamic disulfide bonds in the 3D cross-linked network endow CNGPE rapid self-healing ability at ambient temperature. In addition, the addition of lithium difluoro(oxalato)borate (LiDFOB) and lithium nitrate (LiNO3) helps to form a stable solid electrolyte interface (SEI). Due to the ingenious design, the Li/CNGPE/Li symmetrical cell exhibits excellent interface stability and no short circuit occurs for more than 800 h. The assembled LiFePO4/CNGPE/Li cell exhibits a discharge specific capacity of 126 mAh g−1 after 960 cycles at 0.5C. This work has shown that the self-healing gel polymer electrolyte containing DES provides an effective and feasible method for the development of high-performance LMBs.

A Cross-Linked Gel Polymer Electrolyte Composed of PEGDA and Acrylonitrile for High-Voltage Lithium Metal Batteries

A Cross-Linked Gel Polymer Electrolyte Composed of PEGDA and Acrylonitrile for High-Voltage Lithium Metal Batteries

In-Situ Cross-linked F- and P-Containing Solid Polymer Electrolyte for Long-Cycling and High-Safety Lithium Metal Batteries with Various Cathode Materials.

The practical application of lithium metal batteries (LMBs) has been hindered by limited cycle-life and safety concerns. To solve these problems, we develop a novel fluorinated phosphate cross-linker for gel polymer electrolyte in high-voltage LMBs, achieving superior electrochemical performance and high safety simultaneously. The fluorinated phosphate cross-linked gel polymer electrolyte (FP-GPE) by in-situ polymerization method not only demonstrates high oxidation stability but also exhibits excellent compatibility with lithium metal anode. LMBs utilizing FP-GPE realize stable cycling even at a high cut-off voltage of 4.6 V (vs Li/Li+) with various high-voltage cathode materials. The LiNi0.6Co0.2Mn0.2O2|FP-GPE|Li battery exhibits an ultralong cycle-life of 1200 cycles with an impressive capacity retention of 80.1 %. Furthermore, the FP-GPE-based batteries display excellent electrochemical performance even at practical conditions, such as high cathode mass loading (20.84 mg cm-2), ultrathin Li (20 μm), and a wide temperature range of -25 to 80 °C. Moreover, the first reported solid-state 18650 cylindrical LMBs have been successfully fabricated and demonstrate exceptional safety under mechanical abuse. Additionally, the industry-level 18650 cylindrical LiMn2O4|FP-GPE|Li4Ti5O12 cells demonstrate a remarkable cycle-life of 1400 cycles. Therefore, the impressive electrochemical performance and high safety in practical batteries demonstrate a substantial potential of well-designed FP-GPE for large-scale industrial applications.

3D cross-linked POSS-containing borate single ion conductor organic-inorganic hybrid gel electrolytes for dendrite-free lithium metal batteries

At present, lithium (Li) metal has become the most promising anode for the next generation of batteries due to its excellent theoretical capacity and low electrochemical potential. Nevertheless, low lithium-ion transference numbers and poor stability between conventional electrolytes and electrodes limit its development. In this work, a novel three-dimensional cross-linked hybrid borate single ion conductor polymer electrolyte (POSS-BSICP) was constructed by coupling of novel synthesized lithium bis-allylmalonate borate (LiBAMB), poly (ethylene glycol) diacrylate (PEGDA) and vinyl-containing caged poly(sesquisiloxane) (MAPOSS) in the presence of pentaerythritol tetrakis(mercaptoacetate) (PETMP) as cross-linker and PVDF-HFP as support materials through UV-thermal Dual-Curing procedures. As expected, the lithium-ion transference number and electrochemical stability of the hybrid electrolyte membranes improve with the incorporation of MAPOSS. The tLi+ is up to 0.82 and the electrochemical window reaches 5.50 V. The Li/Li cell assembled with the POSS-containing single ion conductor gel polymer electrolytes can be subjected to stripping/plating cycles without short circuit over 2700 h at 0.1 mA cm−2, the peak of the SiO bond at 102.3 eV in the Si 2p spectrum confirms that the POSS participate in the formation of SEI, indicating that the incorporation of MAPOSS could increase the compatibility between the electrolytes and electrode. The Li|POSS-BSICP|LiFePO4 cell exhibits excellent cycle performance with a capacity retention over 90 % after 170 cycles and 82.0 % after 290 cycles at 0.1 C.

An in-situ cross-linked network PMMA-based gel polymer electrolyte with excellent lithium storage performance

Gel polymer electrolytes (GPEs) effectively combine the advantages of high ionic conductivity and reduce the risk of leakage associated with liquid. In this study, a chemically cross-linked gel polymer electrolyte was prepared by in-situ polymerization using polymethyl methacrylate (PMMA) as a matrix and neopentyl glycol diacrylate (NPGDA) as cross-linking agent. The cross-linked structure of the GPE was preliminarily investigated, as well as the influence of the degree of cross-linking on its physical properties. The GPE exhibited a superior conductivity of 1.391 mS cm−1 at 25 °C. Herein, the Li|GPE|LiNi0.8Co0.1Mn0.1O2 cell has an excellent capacity retention rate of 80.7% after 150 cycles at 0.5 C in addition to a high discharge specific capacity of 203 mAh g−1. The structure of the cathode material is shielded from the production of byproducts during the charging and discharging of lithium-ion batteries by the cross-linked PMMA GPE.

Facile fabrication of cross-linked polymer electrolyte via imidazole-based deep eutectic solvent-induced in situ polymerizations

Fabricating the cross-linked network is an efficient strategy for improving the mechanical and electrochemical performances of polymer electrolytes (PEs). However, present methods used for the preparation of the cross-linked PEs is difficult to remove the residual catalyst and avoid the side reactions, and the ion conduction in solid PEs is often confined. Herein, we report that the deep eutectic solvent (DES) via the Li–N interaction of 1,2-dimethylimidazole (DMIm) and bis(trifluoromethane)sulfonimide lithium (LiTFSI) displays synergistic effects in inducing the ring-opening polymerization (ROP) of trimethylene carbonate (TMC) and thiol-Michael addition reaction, permitting in situ preparation of PEs with a cross-linked structure. Moreover, DMIm-based DES not only endows PEs with the flame-retardant property but also promotes the conduction of Li ions (Li+) in PEs, leading to a good ionic conductivity at 60 °C (1.8 × 10−4 S cm−1) and Li+ transference number (0.41). Notably, no obvious short-circuit at 0.1 mA cm−2 appears during the deposition process of lithium symmetric batteries assembled with PEs after 1200 h.

A strong nucleophilic fluorination agent to achieve highly stable in-situ 3D cross-linked gel polymer electrolyte for lithium-ion batteries

The Gel Polymer Electrolyte (GPE) is recognized as a promising alternative to conventional electrolytes, aiming to enhance the longevity and energy density of lithium-ion batteries (LIBs). However, several challenges persist, particularly concerning the conductivity and voltage window of GPE in battery systems. In this study, we introduce an in-situ 3D crosslinked GPE, using polymethyl methacrylate (PMMA) as the monomer and polyethylene glycol dimethacrylate (PEGDMA) as the crosslinking agent, to ensure structural stability and optimized ion conductivity. We also incorporate a potent nucleophilic fluorination agent, Tetrabutylammonium fluoride (TBAF), to augment the compatibility and oxidation resistance of the formulated FGPPE. The recurring (–CH2CH2O-) units of PEGDMA, coupled with in-situ lithium fluoride (LiF) and C-F groups introduced by TBAF, endow the FGPPE with a remarkable ionic conductivity of 7.8 mS cm−1 and a distinctly electrochemical stability of 4.65 V. Notably, the Li metal anode, featuring an F-rich solid-state interface (SEI), demonstrates uniform Li+ deposition, sustaining a cycling life of 1000 h and maintaining a commendable average coulomb efficiency of 98.5 % over 300 cycles. Additionally, the NCM811/SiC pouch cell integrated with FGPPE showcases superior cycling stability, retaining 99.4 % of its capacity after 600 cycles at an elevated voltage of 4.45 V. Such advancements in gel polymer electrolyte design can significantly expedite the commercial deployment of gel polymer Li-ion batteries.

A glycerol triglycidyl ether cross-linker assisting an in situ thermally polymerized gel polymer electrolyte for advanced lithium metal batteries

A novel cross-linked gel polymer electrolyte was prepared by in situ ring-opening polymerization of 1,3-dioxolane (DOL) and glycerol triglycidyl ether (GTE), producing the longest cyclic lifespan in lithium metal batteries.

A Fully Amorphous, Dynamic Cross-Linked Polymer Electrolyte for Lithium-Sulfur Batteries Operating at Subzero-Temperatures.

Solid-state lithium-sulfur batteries have shown prospects as safe, high-energy electrochemical storage technology for powering regional electrified transportation. Owing to limited ion mobility in crystalline polymer electrolytes, the battery is incapable of operating at subzero temperature. Addition of liquid plasticizer into the polymer electrolyte improves the Li-ion conductivity yet sacrifices the mechanical strength and interfacial stability with both electrodes. In this work, we showed that by introducing a spherical hyperbranched solid polymer plasticizer into a Li+ -conductive linear polymer matrix, an integrated dynamic cross-linked polymer network was built to maintain fully amorphous in a wide temperature range down to subzero. A quasi-solid polymer electrolyte with a solid mass content >90 % was prepared from the cross-linked polymer network, and demonstrated fast Li+ conduction at a low temperature, high mechanical strength, and stable interfacial chemistry. As a result, solid-state lithium-sulfur batteries employing the new electrolyte delivered high reversible capacity and long cycle life at 25 °C, 0 °C and -10 °C to serve energy storage at complex environmental conditions.

(Invited) All-Solid-State Na- and K-Ion Batteries with Dry Polymer Electrolytes

The development of sodium-ion and potassium-ion batteries has gained increasing attention as a sustainable and cost-effective alternative to lithium-ion batteries, due to the abundance of their constituent elements.[1]-[3] All-solid-state batteries offer high safety advantages in high-temperature conditions, as their solid composition reduces the risk of leakage or ignition of the organic electrolyte. As large-scale and stationary batteries for energy storage applications require safety and durability in wide-temperature operations, all-solid-state sodium-ion and potassium-ion batteries can provide a potential solution.This study presents the fabrication of all-solid-state sodium batteries, using dry polymer electrolytes, optimized for stable operation at 60 °C.[4] A composite electrode with uniformly dispersed conductive carbon and binder polymer is essential to achieve a stable charge-discharge reaction in all-solid-state cell, due to the absence of the liquid electrolyte penetrated in the electrode pores. The use of a polymer electrolyte as a binder polymer provides an effective ionic conduction path inside the electrode, which allows stable charge-discharge reaction even at the thick composite electrodes. The fabricated all-solid-state Na // P2-Na2/3[Ni1/3Mn2/3]O2 cell exhibits superior cycle performance at 60 °C, compared to the liquid electrolyte. Furthermore, coating P2-Na2/3[Ni1/3Mn2/3]O2 with Al-oxide enhances the capacity retention of the P2-Na2/3[Ni1/3Mn2/3]O2 // hard carbon full cell, with a mean discharge voltage of 3.11 V and energy density of 148 Wh (kg of active material)−1. To the best of our knowledge, this is the highest value ever reported for full-cell operation of an all-solid-state sodium-ion battery using a dry-polymer electrolyte.The study also reports the fabrication of all-solid-state potassium batteries, where the effects of K metal pretreatment on the K metal/solid polymer electrolyte interface were investigated.[5] The use of K metal chunk, pretreated with the electrolytes containing potassium bis(fluorosulfonyl)amide (KFSA), effectively suppressed polarization and interfacial resistance during continuous K metal stripping-deposition reactions in the cross-linked polymer electrolyte, poly[ethylene oxide-co-2-(2-methoxyethoxy)ethyl glycidyl ether-co-allyl glycidyl ether] (P(EO/MEEGE/AGE)). The addition of 1,3,2-dioxathiolane 2,2-dioxide (DTD) to the pretreatment solution further decreased polarization and interfacial resistance, due to the formation of a stable passivation layer on K metal by FSA− ions and DTD. The efficient operation of the potassium iron hexacyanoferrate positive electrode and graphite negative electrode in P(EO/MEEGE/AGE), with the K metal counter electrode, was achieved by effectively suppressing interfacial resistance through pretreatment. Stable K metal counter electrode for all-solid-state potassium cell was also beneficial to design full cell of all-solid-state potassium-ion cell, enabling us to fabricate the first 3 V-class all-solid-state K-ion battery operated at room temperature.

Constructing Stable Solid Electrolyte Interphase Using Gel Polymer Electrolytes for Anode-Free Lithium Metal Batteries with Enhanced Cycle Life

Anode-free lithium metal batteries (AFLMBs) have recently emerged as next-generation batteries due to high energy density, reduced cost, and simplified manufacturing process due to the absence of reactive metallic lithium. However, developing high-performance AFLMBs faces several challenges for practical applications, such as low coulombic efficiency and poor cyclability, due to the dendrite growth of lithium and side reactions of lithium with liquid electrolytes. To develop the AFLMBs with long cycle life, it is necessary to attain high coulombic efficiency since there is no excessive lithium to compensate for irreversible Li inventory losses in the AFLMB. Three-dimensional cross-linked gel polymer electrolyte (GPE) can be a good candidate for stabilizing the lithium metal by encapsulating organic solvents in the polymer matrix, leading to reduction of the parasitic reactions between lithium metal and liquid electrolyte, which results in high coulombic efficiency of AFLMBs. In this work, we prepared a cross-linked GPE using a multi-functional cross-linking agent to realize high coulombic efficiency and long cycle life of AFLMBs with LiNixCoyAl1-x-yO2(NCA) cathode (areal capacity of 4.76 mAh cm-2). Moreover, the GPE capable of coordinating with lithium ions could construct stable solid electrolyte interphase by regulating lithium ion solvation structures. Cycling performance was investigated in the voltage range of 3.6 – 4.3 V at 0.5 C rate. The Cu/GPE/NCA cell exhibited a capacity retention of 80% after 150 cycles, which was higher than that of AFLMB with liquid electrolyte. Electrochemical characterization and spectrometry were performed to investigate how the GPE could improve the cycling performance of AFLMBs.

Nonflammable Gel Polymer Electrolyte for Lithium-Ion Batteries with Enhanced Safety and High-Temperature Performance

Lithium-ion batteries (LIBs) have become dominant power sources for various applications such as mobile electronics, electric vehicles and energy storage systems. However, liquid electrolytes currently used in LIBs have critical drawbacks such as flammability and leakage problem. In this regard, various electrolyte systems have been developed to enhance the battery safety while maintaining cycling performance. Among them, the chemically cross-linked gel polymer electrolytes (GPEs) can enhance the thermal safety of LIBs by effectively encapsulating organic solvents in the polymer matrix. However, they usually contain large amounts of organic solvents to achieve high ionic conductivity, making GPE be still flammable. To solve these problems, we designed and synthesized a novel phosphorus-based cross-linking agent with excellent flame retardancy. GPE was prepared by in-situ thermal curing of gel precursor containing liquid electrolyte and phosphorus-based cross-linking agent. The obtained GPE exhibited high ionic conductivity and nonflammability. The GPE was applied to lithium-ion cells composed of graphite anode and LiNi0.6Co0.2Mn0.2O2 cathode. Our results revealed that the lithium-ion cell employing GPE exhibited enhanced safety and improved high-temperature cycling performance compared to the cell with the liquid electrolyte.

Quasi-Solid-State All-V2O5 Battery.

Solid-state symmetrical battery represents a promising paradigm for future battery technology. However, its development is hindered by the deficiency of high-performance bipolar electrodes and compatible solid electrolytes. Herein, a quasi-solid-state all-V2O5 battery constructed by a binder-free carbon fabric-V2O5 nanowires@graphene (CVOG) bipolar electrode and a softly cross-linked polyethylene oxide-based solid polymer electrolyte (SPE) is reported. The synergetic effect of nano-structuring of V2O5, hierarchical conductive network, and graphene wrapping endows the CVOG electrode with boosted reaction kinetics and suppressed vanadium dissolution. The cathodic and anodic reactions of CVOG are decoupled by electrochemical analysis, conceiving the feasibility of constructing all-V2O5 full battery. In manifesting the solid-state all-V2O5 battery, the robust and elastic SPE exhibits high ionic conductivity, tight/self-adaptable electrolyte-electrode contact, and a low charge-transfer barrier. The resultant solid-state full battery exhibits a high reversible capacity of 158mAhg-1 at 0.1C, good capacity retention of over 61% from 0.1C to 2C, and remarkable cycling stability of 77% capacity retention after 1000 cycles at 1C, which surpass other solid-state symmetrical batteries. Hence, this work provides a practice of high-performance solid-state batteries with symmetrical configuration and is constructive for next-generation battery technology.

Dual-type gel polymer electrolyte for high-voltage lithium metal batteries with excellent cycle life

The most attractive approach for maximizing the energy density of rechargeable lithium batteries is to combine a lithium metal anode with a high-voltage cathode. However, the dendritic formation of lithium at the anode and the highly oxidizing conditions that cause electrolyte decomposition at the cathode have hindered the practical development of lithium metal batteries (LMBs). In this study, we report a dual-type gel polymer electrolyte (GPE) composed of an anolyte and a catholyte that can address the drawbacks of both the anode and cathode sides. The anolyte is a poly(ethylene oxide)-based composite solid polymer electrolyte that is chemically stable with lithium metal and has a high mechanical strength for suppressing lithium dendrite growth. A cross-linked gel polymer electrolyte with high lithium-ion conductivity and oxidative stability was used as the catholyte. The Li/LiCoO2 cell assembled with a dual-type GPE exhibited a high discharge capacity of 181.1 mAh g−1 (areal capacity: 3.15 mAh cm−2) in the voltage range of 3.0–4.5 V and excellent cycle life, with a capacity retention of 74 % after 700 cycles at 25 °C and 0.5 C rate. Our study proposes a promising electrolyte system for LMBs with high energy density and good cycle life.

Solvation structure reorganization and interface regulation of poly (glycidyl POSS)-based electrolyte for quasi-solid-state lithium-ion batteries

The interfacial stability and some unexpected side reactions in quasi-solid-state lithium-ion batteries (LIBs) impede the practical application of the in-situ crosslinked polymer electrolytes. Herein, a novel in-situ crosslinked polymer electrolyte with eight-armed crosslinked supramolecular structure is constructed via cationic ring-opening polymerization of glycidyl polyhedral oligomeric silsesquioxane (POSS). The strong electrostatic and hydrogen bonding interactions of the POSS blocks with anions reorganize the solvation structure, and the overall oxidation resistance of anions can be also effectively enhanced benefiting from the relatively electron-withdrawing effect of the POSS blocks. Simultaneously, a hierarchical cathode-electrolyte interphase with flexibility and oxidation resistance is constructed involving the boron difluoride radical-catalyzed cleavage of Si-O-Si linkages in POSS frameworks. The poly (glycidyl POSS)-based electrolyte enables the Li||NCM83 cell to possess a high capacity retention of 79.1 % after 500 cycles. Moreover, the SiOx||NCM83 battery shows a capacity retention of 87.6 % after 200 cycles. These insights gained form this work opens up an avenue for the development and practical application of quasi-solid-state LIBs.

Cross-Linked Composite Polymer Electrolyte Doped with Li6.4La3Zr1.4Ta0.6O12

Interfacial studies were performed on Li-ion conducting solid electrolytes based on cross-linked composite polymer electrolytes (CPEs) with different volume fractions of lithium lanthanum zirconium oxide (LLZTO). Dendrite-free protrusion could be achieved with excellent interfacial stability at current density of 400 mA/cm2 (figure 1)and higher with excellent ionic conductivity of 1.1 × 10−4 S cm−1 at 40 °C. An all-solid-state full cell was fabricated with LiNi0.6Mn0.2Co0.2O2 (NMC) as the cathode and 20 µm of lithium on 15 µm copper anode as well as Li chip (270 µm) for comparison. The cells delivered a capacity of ca. 130 mAh g−1, which proved the effectiveness of the electrolyte. The effect of the different volume fractions on the interfacial properties and the architecture of embedded the solid electrolyte in the cathode will be discussed. Figure 1

Iron-Based Cathode Material for Lithium Ions and Metal Batteries

Metal oxyfluoride conversion cathodes are very attractive as high energy material due to their high redox reactions because of the high electronegativity of fluorine atom. It has been demonstrated that the rutile structure of FeOF has been obtained, but there are only a few reports about the cubic phase of FeOF. In this study, we are demonstrated a cubic phase of FeOF can be obtained after charging and discharging a mixture of ball milled LiF/FeO at 750 rpm for 12 hours. Although, X-ray diffraction did not show the presence of Fe+3 in the starting material, X-ray-photo electron spectroscopy revealed the presence of Fe+3 suboxides. Excellent cycling stability was obtained and a cell was cycled at 50 mA/g in liquid electrolyte. We also demonstrate long-cycle stability for over 200 cycles at 40 °C when a solid electrolyte was used. The solid electrolyte was embedded with a cross-linked composite polymer electrolyte to improve transport of lithium ion inside the cathode. The electrochemical properties of both the lithium ion and the lithium metal properties will be compared. Figure 1