The deposition of a thin LixSny alloy layer by plasma vapor deposition (PVD) on the surface of a Li foil is reported. The formation of a Li-rich alloy is confirmed by the volume expansion (up to 380%) of the layer and by the disappearance of metallic Sn peaks in the X-ray diffractogram. The layer has a much higher hardness than bare Li and can withstand aggressive cycling at 1C. Post-mortem scanning electron microscope observations revealed that the alloy layer remains intact even after fast cycling for hundreds of cycles. A concept of double modification by adding a thin ceramic/polymer layer deposited by a doctor blade on top of the LixSny layer was also reported to be efficient to reach long-term stability for 500 cycles at C/3. Finally, a post-treatment after Sn deposition consisting of a plasma cleaning of the LixSny alloy layer led to a strong improvement in the cycling performance at 1C. The surface is smoother and less oxidized after this treatment. The combination of a Li-rich alloy interlayer, the increase in hardness at the electrolyte/Li interface, and the absence of dissolution of the layer during cycling at high C-rates are reasons for such an improvement in electrochemical performance.

All-solid-state batteries are known to be the new energy storage holy grail that will lead to safer batteries with higher energy density than current Li-ion batteries. The use of a solid electrolyte enables the use of lithium metal as the anode material. However, its composition, its thickness and the quality/nature of its passivation layer can strongly affect the performance of the battery. For this reason, we propose a simple benchmarking method that evaluates and compares the quality and electrochemical performance of various Li anodes. This method can be easily reproduced, especially concerning the electrochemical evaluation that uses a commercial liquid electrolyte and the widely spread coin-cell format. In total, ~285 coin cells were assembled to benchmark our in-house lithium metal foil (Lithium HQ) with two commercial ones and the results showed the superior performance of our Li metal anode. The performance of the cells seems closely related to the quality and uniformity of the Li surface. In addition, we propose including in the benchmarking method the effect of Li aging in a dry room on the electrochemical performance. This effect is important to consider because the fabrication of all-solid-state batteries is conducted in such an environment.

In recent years, solid electrolytes have become an enticing alternative to liquid electrolytes in lithium based batteries. However, the high synthesis temperatures and difficult optimization of solid-state electrolytes are a significant drawback in a high-scale application. In this work, we demonstrate that the synthesis process of garnet-based Li7La3Zr2O12 (LLZO) electrolyte can be accelerated while reducing the formation temperature of cubic LLZO to about 720 degrees C from a standard temperature of 780 degrees C by supplementing the process with a carbon additive. These carbon-rich LLZO samples have a homogeneous particle distribution with a decreased average size, which is influenced by the type of carbon additive itself. The materials with high carbon content show an improved densification after hot-pressing at a low temperature of 800 degrees C, which is reflected in their electro-chemical performance, since LLZO sample with 10% of DENKA carbon additive shows a total ionic conductivity of 5.95 x 10-5 S cm-1, about 40% higher than the one of carbon-free LLZO (3.53 x 10-5 S cm-1).

All-solid-state batteries (ASSB) require stable and safe Li metal anode, which needs surface preparation to increase lithium diffusion and impede the formation of dendrites. In this work, the formation of a thin LiZn layer on lithium metal using sputter deposition is reported. This method was selected due to the absence of solvents and by-products generated during the modification, for its rapidity and because the formation of the alloy is performed in a clean and controlled atmosphere. Zinc has been chosen for its low cost and high Li + ion diffusion coefficient of the corresponding LiZn alloy that is 1000 times higher than lithium. Different parameters for the Zn deposition were investigated such as the distance between the Zn target and Li foil, the effect of substrate tilt and the direct current applied to the target. Electrochemical performance of LiFePO 4 /solid polymer electrolyte/Li ASSB demonstrated the superiority of the LiZn anodes and the clear influence of deposition parameters on the durability and performance at high C-rates. Scanning electron microscopy images of the cross-sectional view of LFP/SPE/Li stackings extracted from pouch cells after cycling showed an evident migration of Zn into the bulk Li metal anode as well as the formation of AlZn nanoparticles. In addition, the formation of Li dendrites was effectively reduced for the cells made with the LiZn-protected Li metal anode. Finally, we reported an interesting observation concerning the influence of sputter conditions on the variation of morphology of Li grains.

In this work, we investigated the origin of lithiophilicity of a Cu foil substrate modified by a sputtered Zn thin film (Cu@Zn) in contact with a molten Li metal to understand the reaction mechanism between Li and Cu@Zn. We studied the reaction between the molten Li metal and the Cu surface during Li solidification via in situ scanning electron microscopy (SEM), subsequently performed post-mortem energy dispersive spectroscopy (EDS) and Grazing Incidence X-ray Diffraction (GIXRD) on the coatings to analyze the chemistry of the reaction products, and compared the results for different thicknesses of nanometric Zn films (5-50 nm). For the first time in the literature, we report the existence of a metastable ternary Li-Cu-Zn alloy at 300 degrees C after the reaction of Cu@Zn with the molten Li metal. We also report the segregation of Cu and Zn by formation of Cu-Zn intermetallic compounds during the cooling down step. The results of our in situ study are pivotal to clarify the interfacial reactions occurring between a lithiophilic current collector and a molten Li metal and have utmost importance for designing advanced anode materials for future solid-state battery applications.

Journal Article Understanding the Origin of Lithiophilicity Toward Molten Li-Metal Using In-situ Scanning Electron Microscopy (SEM) Get access Shirin Kaboli, Shirin Kaboli Hydro-Québec’s Center of Excellence in Transportation Electrification and Energy Storage, Varennes, Québec, Canada Search for other works by this author on: Oxford Academic Google Scholar Wen Zhu, Wen Zhu Hydro-Québec’s Center of Excellence in Transportation Electrification and Energy Storage, Varennes, Québec, Canada Search for other works by this author on: Oxford Academic Google Scholar Daniel Clément, Daniel Clément Hydro-Québec’s Center of Excellence in Transportation Electrification and Energy Storage, Varennes, Québec, Canada Search for other works by this author on: Oxford Academic Google Scholar Martin Dontigny, Martin Dontigny Hydro-Québec’s Center of Excellence in Transportation Electrification and Energy Storage, Varennes, Québec, Canada Search for other works by this author on: Oxford Academic Google Scholar Frédéric Gendron, Frédéric Gendron Hydro-Québec’s Center of Excellence in Transportation Electrification and Energy Storage, Varennes, Québec, Canada Search for other works by this author on: Oxford Academic Google Scholar Kamyab Amouzegar, Kamyab Amouzegar Hydro-Québec’s Center of Excellence in Transportation Electrification and Energy Storage, Varennes, Québec, Canada Search for other works by this author on: Oxford Academic Google Scholar Ashok Vijh, Ashok Vijh Hydro-Québec’s Center of Excellence in Transportation Electrification and Energy Storage, Varennes, Québec, Canada Search for other works by this author on: Oxford Academic Google Scholar Abdelbast Guerfi, Abdelbast Guerfi Hydro-Québec’s Center of Excellence in Transportation Electrification and Energy Storage, Varennes, Québec, Canada Search for other works by this author on: Oxford Academic Google Scholar Michel L Trudeau, Michel L Trudeau Hydro-Québec’s Center of Excellence in Transportation Electrification and Energy Storage, Varennes, Québec, Canada Corresponding author: Trudeau.Michel@hydroquebec.com Search for other works by this author on: Oxford Academic Google Scholar Andrea Paolella Andrea Paolella Hydro-Québec’s Center of Excellence in Transportation Electrification and Energy Storage, Varennes, Québec, CanadaAustrian Institute of Technology, Battery Technologies, Wien, Austria Search for other works by this author on: Oxford Academic Google Scholar Microscopy and Microanalysis, Volume 29, Issue Supplement_1, 1 August 2023, Pages 1333–1334, https://doi.org/10.1093/micmic/ozad067.683 Published: 22 July 2023

We report the effect of using rutile and anatase TiO2 as precursors in the synthesis of ceramic Li1.3Al0.3Ti1.7(PO4)(3) (LATP) NASICON-type electrolyte for solid-state lithium batteries. Anatase TiO2 enables LATP crystallization at lower temperatures while rutile TiO2 leads to a purer and more crystalline LATP phase. We believe these findings are an important contribution towards the development of more effective and less expensive synthesis of Ti-based solid electrolyte materials.

All-solid-state batteries (ASSB) require stable and safe lithium (Li) metal anode, which needs surface preparation to increase lithium diffusion and impede the formation of dendrites. In this work, the formation of a thin LiZn layer on lithium metal using sputter deposition is reported. This method was selected due to the absence of solvents and by-products generated during the modification, for its rapidity and because the formation of the alloy is performed in a clean and controlled atmosphere. Zinc has been chosen for its low cost and high Li ion diffusion coefficient of the corresponding LiZn alloy that is 1000 times higher than Li. Different parameters for the Zn deposition were investigated such as the distance between the Zn target and Li foil, the effect of substrate tilt and the direct current applied to the target. Electrochemical performance of LiFePO4/solid polymer electrolyte/Li ASSB demonstrated the superiority of the LiZn anodes and the clear influence of deposition parameters on the durability and performance at high C-rates. Scanning electron microscopy images of the cross-sectional view of LFP/ SPE/Li stackings extracted from pouch cells after cycling showed an evident migration of Zn into the bulk Li metal anode as well as the formation of AIZn nanoparticles.

One of the main limitations to the application of anode free lithium battery is low Coulombic efficiency, this loss of capacity is due to irreversible processes, mainly the formation of dead lithium, the instability of electrolyte, etc. In this work, conventional x-ray diffraction technique was employed to monitor the lithium metal plating and stripping during cycling between 4.3 and 3 V using cells composed of 5 mu m thick copper current collector and LiN0.8Co0.1Mn0.1O2 cathode. We have observed that the lithium metal was not completely stripped off from the copper substrate at the end of discharge at a slow cycling rate of C/24 even in the first 2 cycles. In addition, the lithium metal was still seen following a constant voltage period of 3V despite at its reduced amount. The observation of this unreacted lithium metal unveils one of the important degradation mechanisms of anode free lithium battery, thus provides essential information for finding solution to reduce/ eliminate "dead " lithium metal and prolonging cycling life.

The deposition of thin layers of polymer/ceramic on a lithium surface to produce a strong barrier against dendrites was demonstrated. Different forms (needle, sphere, rod) and types of ceramic (Al2O3, Mg2B2O5) were tested and polymer/ceramic interlayers of a few micrometers (4 μm minimum) between the lithium and the PEO-based solid polymer electrolyte (SPE) were deposited. Interlayers with high amounts of ceramic up to 85 wt% were successfully coated on the surface of lithium foil. Compact "polymer in ceramic" layers were observed when Al2O3 spheres were used for instance, providing a strong barrier against the progression of dendrites as well as a buffer layer to alleviate the lithium deformation during stripping/plating cycles. The electrochemical performance of the lithium anodes was assessed in symmetrical Li/SPE/Li cells and in full all-solid-state LiFePO4 (LFP)/SPE/Li batteries. It was observed for all the cells that the charge transfer resistance was significantly reduced after the deposition of the polymer/ceramic layers on the lithium surface. In addition, the symmetrical cells were able to cycle at higher C-rates and the durability at C/4 was even improved by a factor of 8. Microscopic observations of Li/SPE/Li stacks after cycling revealed that the polymer/ceramic interlayer reduces the deformation of lithium upon cycling and avoids the formation of dendrites. Finally, LFP/SPE/Li batteries were cycled and better coulombic efficiencies as well as capacity retentions were obtained with the modified lithium electrodes. This work is patent-pending (WO2021/159209A1).

The electrochemical performance of Al-doped and un-doped Li1+xNi0.6Co0.2Mn0.2O2 (NCM) cathodes was evaluated at a high cut-off voltage up to 4.6 V (vs Li/Li+) using 1 Ah pouch-type full cells and coin-type half cells. The batteries employing Al-doped NCM exhibited lower internal resistance, higher C-rate capability, and better low-temperature performance. In situ X-ray diffraction revealed that the Al-doped cathode followed a one-phase reaction route, which is attributed to enhanced Li+ diffusion due to Al doping and the relatively small and porous secondary particles. The existence of the pristine phase in undoped NCM throughout the cycling is explained by the slow diffusion of lithium in and out of the large and dense particles, leading to phase separation caused by regions with different lithium concentrations. Analysis using time-of-flight secondary ion mass spectrometry combined with a focused ion-beam scanning electron microscopy confirmed that the Li-ion distribution of undoped NCM was less homogeneous than that of the doped NCM.

In this work, we reported the easy incorporation of high amount of flame retardants in Li-ion batteries without affecting the electrochemical performance through grafting on alumina surface. The strategy consisted to firstly graft halogen- and phosphorus-based molecules on Al2O3 surface and then to incorporate the modified ceramics in the porosity of a thermally stable cellulose separator. The final composite separator was analyzed by thermogravimetric and flame test analyses. The results revealed that the use of flame retardant ceramics in the cellulose matrix was an effective method to increase the thermal stability of the separator and slow down and even avoid its combustion. The electrochemical performance of NMC/graphite Li-ion batteries assembled with the various cellulose separators were similar and even slightly better than those obtained for the cell made with a Celgard separator.

Due to increasing demand in energy storage, much attention has been paid to Si as an anode material in Li-Ion batteries because of its theoretical capacity (3579 mAh/g in the Li 15 Si 4 alloy vs 372 mAh/g for graphitic carbon). However, silicon suffers from several drawbacks, including rapid pulverization and SEI ripening, limiting its use. Nanostructuration and protection of silicon with a carbon coating are proven methods to improve the behavior of silicon-based anodes [1]. Using the laser pyrolysis method, the synthesis of silicon-carbon core-shell nanoparticles was achieved in a continuous way, without intermediate manipulations between the synthesis of the core from silane precursor and the shell from ethylene [2]. The influence of the carbon coating on electrochemical performances was studied in coin cells in operando conditions by using electrochemical impedance spectroscopy (EIS) as well as post mortem analysis of the anode by using (X-Ray Photon electron Spectroscopy (XPS), Scanning Electron Microscopy (SEM) and High Resolution Transmission Electron Microscopy (HRTEM)). Special attention was paid to the first cycle because of its major importance in the formation and growth of the SEI and the long term behavior of the battery. By comparing measurements on Si and Si@C materials, EIS clearly demonstrates the beneficial effect of the carbon shell in the SEI stabilization. The stability of the the SEI resistance shows the protective effect of the the carbon shell while the SEI resistance is strongly modified and increases during lithiation. Such behavior can be related to the evolution of the chemical composition determined by XPS at different potentials during lithiation and delithiation. Figure 1

We present the first results of in situ scanning electron microscopy (SEM) of an all-solid Li battery with a nickel-manganese-cobalt-oxide (NMC-622) cathode at 50 °C and an operating voltage of 2.7-4.3 V. Experiments were conducted under a constant current at several C rates (nC rate: cycling in 1/n h): C/12, C/6, and C/3. The microstructure evolution during cycling was monitored by continuous secondary electron imaging. We found that the chemical degradation of the solid polymer electrolyte (SPE) was the main mechanism for battery failure. This degradation was observed in the form of a gradual thinning of the SPE as a function of cycling time, resulting in gas generation from the cell. We also present various dynamic electrochemical and mechanical phenomena, as observed by SEM images, and compare the performance of this battery with that of an all-solid Li battery with a LiFePO4 cathode.

A Li4Ti5O12(LTO) anode material was coated with a Li-rich PTCLi4organic molecule using a spray-dryer technique to increase the Li-ion transfer at the electrode–electrolyte interface enabling battery cycling at sub-zero temperatures.

An in situ surface observation reveals the surface structural changes during heating of a Li–10 wt % Mg alloy sheet.

We report on the synthesis of amphiphilic polymers with a composition shift of the hydrophobic block made by emulsion polymerization that is used as a water-based binder for LiFePO4 cathodes. The integrity of the electrode is sustained by using a unique chemical procedure for cross-linking the binder. This technique yields higher adhesion of the binder on aluminium collectors comparing with the state-of-the-art binders. Amphiphilic polymers are excellent for well-dispersed inorganic particles, and consequently demonstrate satisfactory electrochemical performances.

This work focuses on the stability of hybrid electrochromic displays that use only one electrochromic film, an industrial solid polymer electrolyte and a metallic counter electrode. The lifetime of these devices exceeds 200,000 cycles in tests with three different voltage ranges. Traces of metal deposits were found during cycling, which indicates that the metallic counter electrode combines the functions of current collector and counter electrode. (C) 2016 Elsevier Ltd. All rights reserved.

We report results obtained with lithium 4,5-dicyano-2-(trifluoromethyl) imidazolide (LiTDI), which we believe is a promising lithium salt for electrolytes in lithium-ion batteries. This "Huckel"-type salt has high charge delocalizations which contribute to good lithium-ion dissociation. In addition, it has high thermal stability and safer degradation products compared to LiPF6, which were identified by TGA-MS. It also does not corrode but passivate the aluminum current collector. Cyclic voltammetry measurements showed a stability up to 4.5 V, which is sufficient for use with standard cathode materials. The power capability of half cells containing LiTDI in EC/DEC was evaluated with standard cathodes used in lithium-ion batteries: LFP, NMC, LCO and LMO. Two LiTDI concentrations were investigated: 1 M and 0.6 M and compared with a reference electrolyte: 1 M LiPF6. In spite of a slightly lower conductivity than the LiPF6, LiTDI (1 M and 0.6 M) shows similar power capability up to 2C with LFP (84% of specific capacity recovered), 10C with NMC (61% of specific capacity recovered), and up to 20C for LMO (88% of specific capacity recovered). Furthermore, better power capability was obtained with 0.6 M LiTDI with LCO, which yielded 82% of specific capacity recovered at 1C (67% for 1 M LiTDI and I M LiPF6). (C) 2015 Elsevier B.V. All rights reserved.

In this paper we report on the synthesis of comb-like copolymers as solid polymer electrolytes (SPE). The synthesis involved anionic polymerization of styrene (St) and 4-vinylanisole (VA) as the followed by grafting of poly(ethylene glycol) monomethyl ether methacrylate (PEGMA) by Atom Transfer Radical Polymerization (ATRP). The comb-like copolymer's structure was analyzed by Fourier transform infrared (FTIR) spectroscopy, nuclear magnetic resonance (NMR) and gel permeation chromatography (GPC). The membranes were made by solvent casting and the morphologies were analyzed by atomic forces microscopy (AFM) and scanning electron microscopy (SEM). We observed that a nano and micro phase separation occurs which improves ionic conductivity. The ionic conductivities were determined by AC Impedance, which showed that the SPEs have good conductivities (10(-5) Scm(-1)) at room temperature owing to the negligible values (<10 kJ mol(-1)) of the activation energies for conductivity. The batteries with these polymers exhibit a capacity of 146 mAh g(-1) at C/24, and no evidence of degradation after intense cycling was observed. However, poor cycle life was observed at C/6 and C/3, which is a consequence of several factors. We partially explain that behavior by arguing that whereas PEO lightly "solvates" Li+ thus slowing Li-ion mobility, and PEGMA chains "solvate" Li ions too strongly, trapping and inhibiting their mobility. (C) 2014 Elsevier B.V. All rights reserved.