Solid Electrolyte Batteries Research Articles

Investigation of the Effects of Cu and Fe/Cu Doping on ZnO Nanoparticles for Application as a Solid Electrolyte Battery

In this work, investigation is done on the effect of doping with copper (Cu) and iron/copper (Fe/Cu) on zinc oxide (ZnO) nanomaterials synthesized through a cost‐effective wet chemical precipitation method for application as a solid‐state electrolyte battery. The scanning electron microscope with energy dispersive X‐ray spectroscopy is used to investigate the morphology and elements presence in Cu and Fe/Cu‐doped ZnO nanoparticles. The X‐ray diffraction data illustrates that the crystallite sizes of pure ZnO, Cu–ZnO, and Fe/Cu–ZnO nanoparticles are 14.86, 13.35, and 10.66 nm, respectively, at the (101) plan calculated by Debye Scherrer's formula. The UV‐Vis absorption spectrum shows that the band gap energies of ZnO, Cu–ZnO, Fe–ZnO, and Fe/Cu–ZnO nanoparticles are identified as 3.382, 3.690, 3.5, and 3.465 eV, respectively. The electrical characterization revealed maximum impedance in Fe/Cu–ZnO nanoparticles with 400 Ω at 1 KHz frequency in comparison to other samples. The current–voltage (I–V) measurement shows that the current sensitivity and electrical conductivity are both enhanced for Fe/Cu–ZnO nanoparticles. Fe and Cu co‐doping improved the electrical characteristics of ZnO, and the Fe/Cu–ZnO nanoparticles are employed as a solid electrolyte in a battery, which achieved a high specific charge capacity of 657.85 mAh g−1.

(Invited) Advanced Electrode Processing for Next Generation Batteries

The development of environmentally friendly processing techniques is a key requisite for future sustainable battery development. The so-called DRYtraec® process is a solvent-free process developed as a viable approach to replace slurry-based binders by fibrous polymers and produce laminated electrodes with a low carbon footprint. It has been demonstrated to work for both, liquid and solid electrolyte batteries. NMC cathodes can be produced in a wide range of loading. For lithium sulfur batteries carbon/sulfur composites can be processed without sulfur loss. In particular in the field of solid state batteries it shows significant advantages. All-solid-state lithium-ion batteries are promising candidates to overcome safety and energy limitations of established lithium-ion batteries (LIBs). Excellent results have been reported for sulfide based electrolytes on a small scale. More and more companies announce their first pilot production lines. Therefore, scalable concepts for material and component development are of crucial need. We evaluate this process for the fabrication of thin argyrodite separator films and compare it with slurry-based separators in ASSBs. To test new cell concepts and components under relevant conditions, it is important to manufacture prototype cells with thin separator layers and flexible housing. Therefore, we prepared slurry-free pouch cells based on Ni-rich NMC cathodes and PVD-synthesized Si anodes.The presentation highlights recent developments of the DRYtraec® process and its application to ASSBs, LiS and LIBs.

A Comparative Review of Models for All-Solid-State Li-Ion Batteries

In recent times, there has been significant enthusiasm for the development of all-solid-state Li-ion batteries. This interest stems from a dual focus on safety—addressing concerns related to toxic and flammable organic liquid electrolytes—and the pursuit of high energy density. While liquid electrolyte batteries currently constitute the vast majority of commercial cells, solid electrolyte batteries show great promise. In parallel with experimental research, computational models clarify several fundamental physics that take place throughout battery operations. Giving up on reviewing a broad screening of the existing literature, we set out to select here a few highly relevant models, emphasizing some fundamental conceptual advancements and offering an in-depth and critical insight into the current state of the art. The papers we selected aim at providing the reader with a tangible and quantitative understanding of how all-solid-state Li-ion batteries operate, including the different mechanisms at play and the mathematical tools required to model the pertinent physics and mechanics.

Study of Addition Metal (Ti, Zn) Dopan on the Structure of NASICON as Solid Electrolyte Batteries

This study aims to analysized the effect of addition doped metal (Ti and Zn) on NASICON structure to morphology, materials structure, and electrochemical performance especially ionic conductivity properties. NASICON is a sodium super ionic conductor that it could be as solid electrolyte batteries. One of the problems that exist in the secondary battery is the low working temperature of the electrolyte, which makes it easy to explode when exposed to free air. The common electrolyte in liquid phase, so NASICON as replacement alternative. The synthesis method used is the solid-state reaction method by mixing sodium carbonate, silicon dioxide, zirconium oxide, ammonium dihydrogen phosphate, doped metal (titanium oxide and zinc oxide) and some anhydrous ethanol into a planetary ball mill, dried then calcined. Then the material is pressed to produce pellets and the sintered. The doping used varies from 0 to 5 mol% of titanium and zinc. XRD results showed that all variations in titanium doped had found rhombohedral and monoclinic. whereas in zinc doping also have those phase. The highest ionic conductivity is 7.8x10-3 S/m on 2% mol Zinc Addition

Investigation of Interfacial Behavior of Ni-Rich NCM Cathode Particles in Sulfide-Based Solid-State Electrolyte

All-solid-state batteries (ASSBs) are currently investigated as a future battery technology with conventional layered cathode materials because they can offer benefits in the gravimetric and volumetric energy densities compared to flammable liquid electrolyte lithium-ion batteries with graphite intercalation anode. The solid electrolyte is believed to suppress dendritic growth and low Coulombic efficiency on the lithium metal anode side, which are the key issues for the use of a lithium metal electrode in conventional batteries with liquid electrolyte. Moreover, layered transition metal oxides such as LiNixCoyMnzO2 (NCM, 0 < x, y, z < 1) are one of the most promising positive electrode active material candidates being developed to increase the energy density. In particular, recent studies have shown a tendency to decrease the cobalt content and increase the nickel content to increase energy density and price competitiveness, so high-nickel NCM can be the optimal material suitable for this purpose. However, the remaining interfacial challenges of the cathode / solid electrolyte interface still need to be solved.Herein, we investigated the kinetics such as charge transfer resistance at the interface between high nickel (Ni0.94) NCM particles and argyrodite (Li6PS5Cl) solid electrolytes using the microcavity electrode with the negative and positive pulsed current measurement technique and compared with liquid electrolytes using the same manner measurement technique. The cavity-electrode system is adopted to analyze the electrochemical properties of active particles and electrolytes confined in the cavity to exclude the effects of surrounding interfaces, barriers, and side reactions caused by battery components around the electrodes and the impact of loading and current collectors of the composite electrode. Therefore, understanding the electrode-electrolyte interface between cathode active particles and solid electrolytes is crucial for theoretical studies on the interfacial phenomenon in solid electrolyte batteries.

Graphyne-based membrane as a promising candidate for Li-Battery electrodes protection: Insight from atomistic simulations

All-solid electrolytes could lead to a technological breakthrough in the performance of all-solid-state batteries when combined with a lithium-metal anode. However, the use of a lithium-metal anode presents several challenges, such as dendrite growth, interface electrochemical stability, formation and propagation of cracks, and delamination of the electrode/electrolyte interfaces. This work aims to explore the effectiveness of using newly synthesized 2D graphyne-based membranes (namely graphyne, graphdiyne, and graphtriyne) for electrode protection in a solid polymer electrolyte battery through first-principle calculations, nudged elastic band method, and classical molecular dynamics simulation. Specifically, we aim to investigate the effectiveness of these membranes in mitigating the aforementioned challenges. A high external electric field of up to 0.5 V/Å, 0.75 V/Å, and 1 V/Å was applied to accelerate the ions diffusion process. The adsorption energies, charge transfer, and in-plane/out-plane diffusion of single lithium on graphyne-based surfaces were investigated. Afterward, we calculated and compared the Li+ permeability, the electrolyte molecules’ rejection efficiency, and the intrinsic properties of graphyne-based nanoporous membranes. Our findings show that both graphyne and graphdiyne surfaces effectively permit Li+ intercalation while preventing other electrolyte molecules from reaching the electrodes.

Revealing the role of hydrogen bond coupling structure for enhanced performance of the solid-state electrolyte

Achieving practical applications of PEO-based composite solid electrolyte (CPE) batteries requires the precise design of filler structures at the molecular level to form stable composite interfacial phases, which in turn improve the conductivity of Li+ and inhibit the nucleation growth of lithium dendrites. Some functional fillers suffer from severe agglomeration due to poor compatibility with the polymer base or grain boundary migration, resulting in limited improvement in cell performance. In this paper, ILs@KAP1 is reported as a filler to enhance the performance of PEO-based batteries. Thereinto, the hypercrosslinked phosphorus ligand polymer-containing KAP1, designed at the molecular level, has an abundant porous structure, hydrogen bonding network, and a rigid skeleton structure of benzene rings. These can be used both to improve the flammability with PEO-based and to reduce the crystallinity of the polymer electrolyte. Ionic liquids (ILs) are encapsulated in the nanochannels of KAP1, and thus a 3D Li+ conducting framework could be formed. In this case, it could not only facilitate the wettability of the contact interface with the electrode, significantly promoting its compatibility and providing a fast Li+ transport path, but also facilitate the formation of LiF, Li3N and Li2O rich SEI components, further fostering the uniform deposition/exfoliation of lithium. The LFP||CPE||Li battery assembled with ILs@KAP1-PEO-CPE has a high initial discharge specific capacity about 156 mAh/g at 1C and a remaining capacity about 121.8 mAh/g after 300 cycles (capacity retention of 78.07%).

AlCl3-NaCl-ZnCl2 Secondary Electrolyte in Next-Generation ZEBRA (Na-ZnCl2) Battery

Increasing demand to store intermittent renewable electricity from, e.g., photovoltaic and wind energy, has led to much research and development in large-scale stationary energy storage, for example, ZEBRA batteries (Na-NiCl2 solid electrolyte batteries). Replacing Ni with abundant and low-cost Zn makes the ZEBRA battery more cost-effective. However, few studies were performed on this next-generation ZEBRA (Na-ZnCl2) battery system, particularly on its AlCl3-NaCl-ZnCl2 secondary electrolyte. Its properties such as phase diagrams and vapor pressures are vital for the cell design and optimization. In our previous work, a simulation-assisted method for molten salt electrolyte selection has shown its successful application in development of molten salt batteries. The same method is used here to in-depth study the AlCl3-NaCl-ZnCl2 salt electrolyte in terms of its phase diagrams and vapor pressures via FactSageTM and thermo-analytical techniques (Differential Scanning Calorimetry (DSC) and OptiMeltTM), and their effects on battery performance such as operation safety and charging/discharging reaction mechanism. The DSC and OptiMelt results show that the experimental data such as melting temperatures and phase changes agree well with the simulated phase diagrams. Moreover, the FactSageTM simulation shows that the salt vapor pressure increases significantly with increasing temperature and molar fraction of AlCl3. The obtained phase diagrams and vapor pressures will be used in the secondary electrolyte selection, cell design and battery operation.

Impact of annealing on material and electrical characteristics of lithium phosphate thin films on silicon carbide

In this study, we investigated the influence of post-deposition annealing (PDA) process on lithium phosphate (Li3PO4) solid-state thin films on silicon carbide (SiC) substrate in terms of materials and electrical properties. Li3PO4 thin films were deposited through radio frequency (RF) sputtering and post-deposition annealing was performed in a temperature range of 200–400 °C. The Li3PO4 thin films show typical amorphous structures, and no changes are observed even after 400 °C PDA process. The Li 1 s/P 2p ratio varies with changing the annealing temperature and the highest Li is detected under 300 °C annealing, where the ionic conductivity increases to 1.00 × 10−4 S/mm at the same temperature. The rectification ratio of the 300 °C annealed device is obtained as 1.45 × 103, which is 23 times higher value than as-deposited Li3PO4/SiC device without annealing. This result suggests that the delicate control of Li3PO4 deposition could provide a significant enhancement on the electrical devices and the solid electrolyte batteries.

Mechanical stress-thermodynamic phase-field simulation of lithium dendrite growth in solid electrolyte battery

Growth of lithium dendrites in solid state batteries is an important factor that disturbs their commercial applications. The growth of lithium dendrites at the interface of lithium metal anode will not only lead to the decrease of battery energy efficiency, but also cause combustion, explosion and other safety problems. In order to explore the factors and methods that inhibit the growth of lithium dendrites, the phase-field theory is used to simulate the growth of lithium dendrites in polymer solid electrolyte batteries, and a phase-field model of lithium dendrite growth coupled with mechanical stress and thermal field is established. The effects of key physical factors such as ambient temperature, solid electrolyte Young’s modulus and external stress on dendrite growth and their acting principles are discussed and analyzed. The results show that under the conditions of high temperature, high solid electrolyte Young’s modulus and external stress, the growth of lithium dendrites is slow, the number of long dendrites is small, and the electrodeposition is more uniform. In addition, the effects of Young’s modulus of solid electrolyte and ambient temperature on the growth of lithium dendrites in a common range are compared with each other. It is found that the inhibition effect of changing Young’s modulus of solid electrolyte on the maximum length of lithium dendrites is 19% higher than that caused by the change of ambient temperature.

Recent progresses and challenges in aqueous lithium-air batteries relating to the solid electrolyte separator: A mini-review.

The lithium–air (Li–air) battery utilizes infinite oxygen in the air to store or release energy through a semi-open cathode structure and bears an ultra-high theoretical energy density of more than 1,000 Wh/kg. Therefore, it has been denoted as the candidate for next-generation energy storage in versatile fields such as electric vehicles, telecommunications, and special power supply. Among all types of Li–air batteries, an aqueous Li–air battery bears the advantages of a high theoretical energy density of more than 1,700 Wh/kg and does not have the critical pure oxygen atmosphere issues in a non-aqueous lithium–air battery system, which is more promising for the actual application. To date, great achievements have been made in materials’ design and cell configurations, but critical challenges still remain in the field of the solid electrolyte separator, its related lithium stripping/plating at the lithium anode, and catholyte design. In this mini-review, we summarized recent progress related to the solid electrolyte in aqueous Li–air batteries focusing on both material and battery device development. Moreover, we proposed a discussion and unique outlook on improving solid electrolyte compatibility and battery performance, thus designing an aqueous Li–air battery with higher energy density and better cycle performance in the future.

Mechanical damages in solid electrolyte battery due to electrode volume changes

Mechanical damages in solid electrolytes of solid-state battery (SSB) during the charging-discharging process remain a challenging issue for battery implementation. This paper demonstrates a numerical simulation of the damages in Li10GeP2S12 (LGPS) solid electrolyte of SSB due to compressive loading generated by electrode volume changes. Three models of anode/electrolyte/cathode arrangements were examined numerically with different expansion-shrinkage behavior. Crack formation inside the electrolyte models was realized by inserting cohesive elements, following traction-separation law. The result shows that when the cathode shrunk and the anode expanded, as occurs in NCM/LGPS/In configuration, the mechanical damages inside the LGPS solid electrolyte are more severe. Due to high-stress generation, there is a plastic deformation in the electrolyte and debonding at the electrode-electrolyte interface. The cracks also appear in both center and edge of the electrolyte because of high-stress concentration. These cracks do not occur when Li4Ti5O12 (LTO) anode with a very low expansion rate is used. This finding confirms that SSB was prone to mechanical damages due to expansion-shrinkage behavior in the electrodes, meaning that the mechanical strength of SSB material constituents must be considered in designing long-lasting SSB.

Toward High-Voltage Solid-State Li-Metal Batteries with Double-Layer Polymer Electrolytes

Solid polymer electrolyte batteries with a Li-metal anode and high-voltage active materials hold promising prospects to increase the energy density and improve the safety of conventional Li-ion batteries. An adequate choice of the polymers used for the cathode (catholyte) and for the separator (electrolyte) to create a sufficient energy gap and improve the chemical compatibility at both the positive electrode and Li-metal anode is required. The present work highlights the advantages of the double-layer polymer electrolyte approach in cells with a LiNixMnyCozO2 active material, a poly(propylene carbonate) (PPC) catholyte, and a poly(ethylene oxide) (PEO) electrolyte. Replacing PEO in the catholyte with PPC results in a remarkably improved cycling performance. In addition, the higher lithium transference number of electrolytes with single lithium ion conductors leads to a smooth cycling of solid-state batteries. Cells with 1 mAh cm–2 deliver 160 mAh g–1, with a capacity retention above 80% over 80 cycles and a Coulombic efficiency close to 100%.

Assessing the Feasibility of a Cold Start Procedure for Solid State Batteries in Automotive Applications

This paper addresses the thermal management of a solid polymer electrolyte battery system, which is currently the only commercialized solid-state battery chemistry. These batteries aim to increase the range of electric vehicles by facilitating a lithium metal anode but are limited by operational temperatures above 60 °C. The feasibility of a cold start procedure is examined, which would enable a solid polymer battery to be used, without preconditioning, in a wide variety of ambient temperatures. The proposed solution involves dividing the solid-state battery into smaller sub-packs, which can be heated and brought online more quickly. Thermal modelling shows a cold start procedure is theoretically feasible when using a small liquid electrolyte lithium battery at the start. The key bottlenecks are the rate at which the solid-state batteries can be heated, and the discharge rates they can provide. After resistive heating is used for the first solid-state module, all subsequent heating can be provided by waste heat from the motor and operating battery modules. Due to the insulation required, the proposed system has lower volumetric, but higher gravimetric energy density than liquid electrolyte systems. This work suggests that with suitable system-level design, solid-state batteries could be widely adopted despite temperature constraints.

(Invited) Semi-Solid Alkali Metal Electrodes Enabling High Critical Current Densities and Accessible Areal Capacities in Solid Electrolyte Batteries

The need for higher energy-density rechargeable batteries has generated interest in alkali metal electrodes paired with solid electrolytes [1]. However, metal penetration and electrolyte fracture at low current densities [2], as well as impedance growth at the metal-solid electrolyte interface due to void formation during cycling at practical current densities (> 0.5 mA cm-2), have emerged as fundamental barriers [3]. Here we demonstrate two semi-solid electrode architectures in which the presence of a minor liquid phase enables high current densities while it preserves the shape retention and packaging advantages of solid electrodes [4]. First, biphasic Na–K alloys selected for controlled liquid fraction between the state-of-charge limits show K+ critical current densities (with a K-β″-Al2O3 electrolyte) that exceed 15 mA cm‒2. Second, introducing a wetting interfacial film of Na–K liquid between a Li metal electrode and Li6.75La3Zr1.75Ta0.25O12 solid electrolyte doubles the critical current density and permits cycling at areal capacities that exceed 3.5 mAh cm‒2. These design approaches hold promise for overcoming electrochemomechanical stability issues that have heretofore limited the performance of solid-state metal batteries.We acknowledge support from the US Department of Energy, Office of Basic Energy Science, through award no. DE-SC0002633 (J. Vetrano, Program Manager).[1] Albertus, P., Babinec, S., Litzelman, S. & Newman, A. Nat. Energy 3, 16–21 (2018).[2] Porz, L. et al. Adv. Energy Mater. 7, 1701003 (2017).[3] Kasemchainan, J. et al. Nat. Mater. 18, 1105–1111 (2019).[4] Park, R.J-Y. et al. Nat Energy 6, 314–322 (2021). Figure 1

Toward a mechanically stable solid electrolyte interphase

Toward a mechanically stable solid electrolyte interphase

Defect Engineering and Anisotropic Modulation of Ionic Transport in Perovskite Solid Electrolyte LixLa(1-x)/3NbO3.

Solid electrolytes, such as perovskite Li3xLa2/1−xTiO3, LixLa(1−x)/3NbO3 and garnet Li7La3Zr2O12 ceramic oxides, have attracted extensive attention in lithium-ion battery research due to their good chemical stability and the improvability of their ionic conductivity with great potential in solid electrolyte battery applications. These solid oxides eliminate safety issues and cycling instability, which are common challenges in the current commercial lithium-ion batteries based on organic liquid electrolytes. However, in practical applications, structural disorders such as point defects and grain boundaries play a dominating role in the ionic transport of these solid electrolytes, where defect engineering to tailor or improve the ionic conductive property is still seldom reported. Here, we demonstrate a defect engineering approach to alter the ionic conductive channels in LixLa(1−x)/3NbO3 (x = 0.1~0.13) electrolytes based on the rearrangements of La sites through a quenching process. The changes in the occupancy and interstitial defects of La ions lead to anisotropic modulation of ionic conductivity with the increase in quenching temperatures. Our trial in this work on the defect engineering of quenched electrolytes will offer opportunities to optimize ionic conductivity and benefit the solid electrolyte battery applications.

Correlating Ion Jumps with Bond Covalency in Solid Electrolytes

The development of Li-ion solid electrolyte batteries will improve battery safety and potentially energy density compared to conventional Li-ion batteries, which have liquid-electrolytes. Solid electrolytes are inorganic polycrystals, so they cannot catch on fire and resist dendrite growth. However, Li-ion conductivity in the solid-electrolyte is relatively slow compared to liquids, so this project focuses on understanding the diffusion mechanism of binary metal halides for the improvement of other superionic materials. This work is inspired by the high conductivity of α-AgI and is based on previous computational work by the Adelstein lab that showed thermally driven bond fluctuations aid in the conduction of Li-ions in Li3InBr6.Since bond character is determined by the interaction of the cation and anion and crystal structure, we simulate both Ag and Cu metal halides in various crystal structures. Each crystal structure (α, β, zinc-blende, or rock-salt) is simulated at three temperatures for AgCl, AgBr, AgI, CuCl, CuBr, and CuI to obtain the activation energy barrier. Diffusivity, jump events, and bond character (ionic or polar-covalent) were calculated for each simulation, which allows us to differentiate between different diffusion mechanisms of Ag and Cu. Our on-going investigation into the silver and copper halides aims to test the hypothesis that fluctuations in bond character help superionic diffusion by correlating ion jumps with bond character.

Solution Processing of Lithium‐Rich Amorphous Li‐La‐Zr‐O Ion Conductor and Its Application for Cycling Durability Improvement of LiCoO2 Cathode as Coating Layer

AbstractLithium‐rich amorphous Li‐La‐Zr‐O (a‐Li‐La‐Zr‐O) electrolyte is successfully synthesized using sol–gel processing method. With unlimited compositions of the amorphous structure, lithium‐rich compositions are systematically investigated to determine optimal composition and optimized processing conditions of a‐Li‐La‐Zr‐O coatings. There is an improvement in ionic conductivity of a‐Li‐La‐Zr‐O with Li content increasing, specifically from 3.0 × 10−8 S cm−1 (Li8La2Zr2O11) to 1.18 × 10−6 S cm−1 (Li18La2Zr2O16), thereby resulting in low activation energy. The high‐ionic‐conductivity a‐Li‐La‐Zr‐O is implemented as an artificial solid electrolyte interface coating layer on cathode materials. The a‐Li‐La‐Zr‐O‐coated LiCoO2 (LCO) and LiNi0.8Mn0.1Co0.1O2 (NMC 811) coin cells exhibit better cycling performance than the bare coin cell at the optimum compositional ratio of a‐Li‐La‐Zr‐O. A‐Li‐La‐Zr‐O can be a promising material for solid electrolyte battery and a potential coating layer for the modification of cathode surface.

Recent Advancements in High-Performance Solid Electrolytes for Li-ion Batteries: Towards a Solid Future

With the emergence of non-conventional energy resources and development of energy storage devices, serious efforts on lithium (Li) based rechargeable solid electrolyte batteries (Li- SEBs) are attaining momentum due to their potential as a safe candidate to replace state-of-the-art conventionally existing flammable organic liquid electrolyte-based Li-ion batteries (LIBs). However, Li-ion conduction in solid electrolytes (SEs) has been one of the major bottlenecks in large scale commercialization of next-generation Li-SEBs. Here, in this review, various challenges in the realization of high-performance Li-SEBs are discussed and recent strategies employed for the development of efficient SEs are reviewed. In addition, special focus is laid on the ionic conductivity enhancement techniques for inorganic (including ceramics, glasses, and glass-ceramics) and polymersbased SEs. The development of novel fabrication routes with controlled parameters and highperformance temperature optimized SEs with stable electrolyte-electrode interfaces are proposed to realize highly efficient Li-SEBs.