Increasing Lithium Content Research Articles

Structural and compositional characterization of RF magnetron cosputtered lithium silicate films: From Li2Si2O5 to lithium-rich Li8SiO6

In this study, the structure and composition of lithium silicate thin films deposited by radio-frequency magnetron cosputtering are investigated. Five compositions ranging from Li2Si2O5 to Li8SiO6 were confirmed by inductively coupled plasma-optical emission spectroscopy, and structural analysis on the evolution of nonbridging oxygens in the thin films was conducted using Fourier transform infrared spectroscopy. It was found that nonbridging oxygens increased as the silicate network breaks apart with the increasing lithium content, which agrees with previous studies on lithium silicates. Thin film impurities were examined using x-ray photoelectron spectroscopy and time of flight secondary ion mass spectroscopy and traced back to target synthesis. This study utilizes a unique synthesis technique for lithium silicate thin films that can be used to model the lithium silicates formed on the surface of silicon anodes in lithium ion batteries and can bridge the understanding between this layer and the influence of silicates on ionic conductivity of the silicon interphase layer.

Structure Evolution from Layered to Spinel during Synthetic Control and Cycling Process of Fe-Containing Li-Rich Cathode Materials for Lithium-Ion Batteries.

As promising cathode materials for lithium-ion batteries (LIBs), Fe-containing Li-rich compounds of Li1+xFe0.1Ni0.15Mn0.55Oy (0 ≤ x ≤ 0.3 and 1.9 ≤ y ≤ 2.05) have been successfully synthesized by calcining the spherical precursors with appropriate amounts of lithium carbonate. The structures, morphologies, and chemical states of these compounds are characterized to better understand the corresponding electrochemical performances. With an increase of lithium content, Li1+xFe0.1Ni0.15Mn0.55Oy evolves from a complex layered-spinel structure to a layered structure. The lithium content also affects the average size and adhesion of the primary particles. At 0.1 C, sample x = 0.1 shows the highest first charge/discharge specific capacities (338.7 and 254.3 mA h g–1), the highest first Coulombic efficiency (75.1%), the lowest first irreversible capacity loss (84.4 mA h g–1), the highest reversible discharge specific capacity, and good rate capability. Notably, voltage fading can be alleviated through the adjustment of structural features. Such superior electrochemical performances of sample x = 0.1 are ascribed to the hierarchical micro-/nanostructure, the harmonious existence of complex layered-spinel phase, and the low charge-transfer resistance. An integral view of structure evolution from layered to spinel during synthetic control and cycling process is provided to broaden the performance scope of Li–Fe–Ni–Mn–O cathodes for LIBs.

Structural, dielectric and impedance spectroscopic studies of Ni0.5Zn0.5−xLixFe2O4 nanocrystalline ferrites

Nanocrystalline lithium substituted Ni–Zn ferrites with composition Ni[Formula: see text]Zn[Formula: see text]Li[Formula: see text]Fe2O4 ([Formula: see text] = 0.00–0.25 in steps of 0.05) were synthesized by the citrate gel auto-combustion method and were sintered at 1000[Formula: see text]C for 4 h in air atmosphere. The structural, dielectric, impedance spectroscopic and magnetic properties were studied by using X-ray diffraction, impedance analyzer and vibrating sample magnetometer respectively. The X-ray diffraction patterns confirm that all samples exhibit a single phase cubic spinel structure. Suitable cation distribution for all compositions has been proposed by using the X-ray diffraction line intensity calculations and the theoretical lattice parameter for each composition was observed in close agreement with the experimental ones and thereby supporting the proposed distribution. An increase in the saturation magnetization was observed up to [Formula: see text] = 0.10 level of Li[Formula: see text] substitution and thereafter magnetization reduced for higher concentrations to the highest level of Li[Formula: see text] substitution. The dielectric constant and the DC resistivity of Ni–Zn–Li ferrites were noticed to decrease with increase in the Li[Formula: see text] ion concentration. The impedance spectroscopic studies by using the Cole–Cole plots were studied in order to obtain the relaxation time, grain resistance and grain capacitance. AC conductivity initially remained almost independent of frequency for lower frequencies and thereafter for higher frequencies the AC conductivity increased with increase of Lithium concentration.

Voltammetric Enhancement of Li-Ion Conduction in Al-Doped Li7–xLa3Zr2O12 Solid Electrolyte

Al-doped Li7–xLa3Zr2O12 is found to be more ionically conductive following voltammetric treatment in an all-solid-state Li|Li7–xLa3Zr2O12|Li cell configuration. This result is consistent with electrical impedance spectroscopy measurements, which reveal that the activation energy for lithium diffusion is reduced from 0.32 to 0.26 eV following voltammetric treatment. The Li deposition–dissolution signal has been observed in the voltammograms, and neutron powder diffraction shows an increase in the lithium content of the Li7–xLa3Zr2O12. Furthermore, X-ray photoelectron spectroscopy indicates a local rearrangement of O, resulting in a reduction of defects following voltammetric treatment, with the enhanced conductivity attributable to both the reduction of defect oxygen and increased lithium content. This work, therefore, reveals such voltammetric treatment as a simple and inexpensive alternative to existing doping approaches to boost the electrochemical performance of Li7–xLa3Zr2O12. The findings can improve...

Preparation and characterization of some lithium – Ion conductors

Zirconate and phosphate based lithium ion conductors namely, Li2ZrO3, Li2-4xZr1+x(PO4)2 (x=0, 0.125, 0.25, 0.35, 0.45) were prepared and characterized with powder X-ray diffraction and electrical conductivity. Li2ZrO3 exhibited the lowest conductivity and in phosphates, it increased initially with increase in lithium concentration and then decreased. The transport number of lithium deduced from blocking electrode method was found to be in the range of 0.79 to 0.89 for Li2ZrO3, whereas for phosphates with x=0, 0.125 and 0.35, tLi+ was better than 0.98. Li0.6Zr1.35(PO4)2, was found compatible in lead-lithium alloys.

Understanding the Origins of Higher Capacities at Faster Rates in Lithium-Excess LixNi2–4x/3Sbx/3O2

The lithium-excess LixNi2–4x/3Sbx/3O2 (LNSO) materials were previously shown to demonstrate higher capacities and improved cyclability with increasing lithium content. While the performance trend is promising, observed capacities are much lower than theoretical capacities, pointing to a need for further understanding of active redox processes in these materials. In this work, we study the electrochemical behavior of the LNSO materials as a function of lithium content and at slow and fast rates. Surprisingly, Li1.15Ni0.47Sb0.38O2 (LNSO-15) exhibits higher discharge capacities at faster rates and traverses distinct voltage curves at slow and fast rates. To understand these two peculiarities, we characterize the redox activity of nickel, antimony, and oxygen at different rates. While experiments confirm some nickel redox activity and oxygen loss, these two mechanisms cannot account for all observed capacity. We propose that the balance of the observed capacity may be due to reversible oxygen redox and that t...

Lithium and boron analysis by LA-ICP-MS results from a bowed PWR rod with contact

A previously published investigation of an irradiated fuel rod from the Ringhals 2 PWR, which was bowed to contact with an adjacent rod, identified a significant but highly localised thinning of the clad wall and increased corrosion. Rod fretting was deemed unlikely due to the adhering oxide covering the surfaces. Local overheating in itself was also deemed insufficient to account for the accelerated corrosion. Instead, an enhanced concentration of lithium due to conditions of local boiling was hypothesised to explain the accelerated corrosion. Studsvik has developed a hot cell coupled LA-ICP-MS (Laser Ablation Inductively Coupled Plasma Mass Spectrometer) equipment that enables a flexible means of isotopic analysis of irradiated fuel and other highly active surfaces. In this work, the equipment was used to investigate the distribution of lithium (7 Li) and boron (11 B) in the outer oxide at the bow contact area. Depth profiling in the clad oxide at the opposite side of the rod to the point of contact, which is considered to have experienced normal operating conditions and which has a typical oxide thickness, evidenced levels of ∼10–20 ppm 7 Li and a 11 B content reaching hundreds of ppm in the outer parts of the oxide, largely in agreement with the expected range of Li and B clad oxide concentrations from previous studies. In the contact area, the 11 B content was similar to the reference condition at the opposite side. The 7 Li content in the outermost oxide closest to the contact was, however, found to be strongly elevated, reaching several hundred ppm. The considerable and highly localised increase in lithium content at the area of enhanced corrosion thus offers strong evidence for a case of lithium induced breakaway corrosion during power operation, when rod-to-rod contact and high enough surface heat flux results in a very local increase in lithium concentration.

The importance of transport property studies for battery electrolytes: revisiting the transport properties of lithium-N-methyl-N-propylpyrrolidinium bis(fluorosulfonyl)imide mixtures.

Transport properties are examined in some detail for samples of the low temperature molten salt N-propyl-N-methyl pyrrolidinium bis(fluorosulfonyl)imide [Pyr13][FSI] from two different commercial suppliers. A similar set of data is presented for two different concentrations of binary lithium-[Pyr13][FSI] salt mixtures from one supplier. A new and significantly different production process is used for the synthesis of Li[FSI] as well as the [Pyr13]+ salt used in the mixtures. Results for the viscosity, conductivity, and self-diffusion coefficients, together with the density and expansivity and apparent molar volume, are reported over the temperature range of (0 to 80) °C. The data for neat [Pyr13][FSI] are discussed in the context of velocity cross correlation (VCC or fij) and Laity resistance (rij) coefficients. Unusually, f+- ∼ f++ < f--. The three resistance coefficients are of similar magnitude indicating all three ion-ion interactions contribute to the transport properties, not just the cation-anion interaction. The composition dependence of the transport properties is compared to previously reported data for the same and related compounds: in contrast to high-temperature molten salt mixtures, this is an exponential dependence. The Nernst-Einstein parameter Δ, which contains information on the correlations of the ionic velocities and is determined by differences in the VCC for the various ion-ion combinations, was calculated for both the neat ionic liquid and its binary mixture. It increases with increasing lithium concentration. The new data set also allows some conclusions with regards to the lithium-[FSI]- coordination environment.

Quantum-chemical modeling of lithiation of a silicon–silicon carbide composite

With the aim of searching for promising anode materials for lithium-ion batteries, quantum-chemical modeling of the introduction of lithium into a silicon layer supported by nitrogen-doped silicon carbide at Li: Si ratios of 1: 1, 2: 1, and 3: 1 has been performed by the density functional theory method with inclusion of gradient correction and periodic boundary conditions. It has been demonstrated that the absorption of lithium by silicon is energetically more favorable than the formation of a metal layer on the silicon surface. As the lithium concentration increases, the energy difference decreases; i.e., the introduction of lithium into silicon becomes increasingly less favorable, the network of silicon atoms is broken down into smaller and smaller pieces, while the layer thickness increases threefold.

Unusual anti-thermal degradation of bismuth NIR luminescence in bismuth doped lithium tantalum silicate laser glasses.

For application of bismuth laser glasses in either fiber amplifier or laser, their performance stability in long run should be understood especially in extreme conditions. However, so far, there are few reports on it. Here, we found, after the cycle experiments on heating and cooling, that the proper increase of lithium content in lithium tantalum silicate laser glass can lead to unusual anti-thermal degradation of bismuth NIR luminescence, which completely differs from the scenario in germanate glass. FTIR, 29Si MAS NMR spectra, absorption and dynamic photoluminescence spectra are employed to unravel how this happens. The results illustrate that it should be due to the decrease of polymerization of silicate glass network, which in turn allows the regeneration at 250°C, and therefore, the content increase of bismuth NIR emission centers. In the meanwhile, we noticed though Bi luminescence can be thermally quenched its peak does not shift along with temperature, which seldom appears in laser materials. The unique property might guarantee the unshift of Bi fiber laser wavelength once such glass was made into fiber devices even as the environmental temperature changes. The role of lithium is discussed in the evolution of glass structures, the suppression of glass heterogeneity, and the thermal stability of Bi luminescence, and it should be helpful to design homogeneous silicate laser glass with outstanding thermal stability.

High hole concentration Li-doped NiZnO thin films grown by photo-assisted metal–organic chemical vapor deposition

High hole concentration Li-doped NiZnO thin films were grown by metal–organic chemical vapor deposition (MOCVD). The crystalline, optical, electrical, and morphological characteristics of the NiZnO films were studied as a function of lithium content. The resistance of the films decreased and the hole concentration greatly increased with increasing lithium content. However, the crystalline and optical properties were observed to degrade as the lithium content was increased. To relieve the degradation, a photo-assisted MOCVD method was used in order to restrict this degradation and this represents a new way to obtain stable high hole concentration NiZnO films.

Structure, phase transition and impedance of Zn1−x Li x O (0.10 ≤ x ≤ 0.70) ceramic

Structural transformations of Li-doped Zn1−xLixO (0.10 ≤ x ≤ 0.70) which was synthesised by solid-state reaction were investigated. XRD carried out on powder specimens of the samples show that they are polycrystalline in nature with a hexagonal wurtzite structure having minor impurities. The result indicates the maximum limit of substitution of Zn atoms by Li is at x = 0.4. The lattice parameter a reduced from 3.01 to 2.99 A, while c reduced from 5.21 to 5.19 A. However, the Zn–O bond length reduced from 1.88 to 1.87 A for the undoped, to x = 0.60 for the doped, respectively. The c/a ratio is 1.73 and is almost constant for all samples. The grain size of the (100) peak of the undoped ZnO is 41.73 nm and that of x = 0.10 is 41.76 nm. For x = 0.2–0.70, the grain size is 41.72 nm indicating that the grain size is almost independent of doping. The SEM results indicate a variation of grain size from 2.18 to 5.15 µm for the undoped ZnO to x = 0.50, which shows increase in grain size and reduction in grain boundaries as doping increases. The results show that x = 0.50 has the highest grain size and the one with the highest transition temperature is x = 0.6. DTA results indicate the structural phase transition temperature of the doped ZnO ranged from ~371 to ~409 K and increased as the amount of Li increases. A single arc is observed in all the impedance plots of the ZnO together with the presence of a relaxation process which is non-Debye. The impedance data show reduced resistance with increase in lithium content. A general increase in dielectric constant with increase in lithium content is observed.

In Situ Raman Spectroscopy Study: Unusual Properties of Sulfur-Polyacrylonitrile As Cathode Material for Lithium Sulfur Battery

Lithium-sulfur battery is now one of the promising rechargeable battery systems among the next-generation energy storage systems due to its high theoretical capacity of 1675 mAh/g, high theoretical energy density of 2500 Wh/kg comparing to the conventional lithium ion battery, and the abundant resources of sulfur in nature. However, several intrinsic drawbacks of sulfur such as poor electronic conductivity, huge volume change during the cycling, dissolution of intermediates, and safety issue of lithium metals as negative electrode, which hinder its progress to be commercialized. In order to overcome those problems, a combination of sulfur and carbon-based material was studied and found an obvious enhancement in the electrochemical performance. Sulfur-polyacrylonitrile (SPAN) compound [1] as one of the sulfur-carbon-based materials, it shows an outstanding ability to prevent the dissolution of intermediates and largely enhances its long-cycle stability, which has been seen a potential material for the lithium-sulfur battery. Although many groups reported different synthesis of the SPAN materials with good cycling abilities, the reaction mechanism of SPAN during the cycling is rarely discussed and still unclear. The structure of SPAN has been reported by several groups, which the sulfur is in favor of small size (Sx, x = 1~3) and connects with carbon on the dehydrated PAN structure. Wei et al. proposed several reaction routes [2], including the cleavage of S-S bonds on the thiolate group (RSSR) to form RSLi or the complete break of C-S to form the RSLi and Li2S at the same time. However, the lithiation reaction is still lacking in direct observation. Therefore, in this study, the SPAN is studied by in situRaman spectroscopy to further elucidate the reaction mechanism. SPAN material was synthesized by grinding sulfur and PAN in a ratio of 4:1. The well-mixed precursor was then transferred into furnace and heated at 350 ℃ for 3 hours under argon atmosphere to obtain black SPAN powder. As comparison, sulfur/conductive carbon black (S/C) composite was prepared in an optimized ratio of 7:3 (sulfur : carbon), and heated at 155 ℃ for 8 hours to insure liquid sulfur was fully absorbed by carbon matrix. The structure of SPAN was characterized by X-ray diffractometer, which all the diffraction peaks of sulfur disappeared and a broad peak has shown at 27 °. This result may relate to the PAN backbone formed a graphite-like structure after the heat treatment. For the Raman spectrum of as-prepared SPAN, peaks found at 171, 301, and 803 cm−1 are assigned as C-S bonds, and peaks found at 481, and 940 cm−1 are related to S-S bonds. This feature is different from S/C composite, which only observed peaks same as elemental sulfur at 150, 216, and 470 cm−1, showing the formation of covalent C-S bonds between sulfur and PAN backbone rather than simple physical absorption between sulfur and carbon composite. The electrodes of SPAN were prepared by coating the slurry (active material: carboxymethyl cellulose: Super P = 8 : 1 : 1) on the aluminum foil and dried in the 70 ℃ oven overnight. For the cycling test, the reversible capacity for first cycle reaches 1473 mAhg-1 based on sulfur content, which is close to the theoretical capacity of sulfur, and the capacity retains ~90% of initial reversible capacity after 50 cycles. This shows excellent electrochemical properties of SPAN cathode material. Then the assembled cell using SPAN cathode was analyzed by in situ Raman spectroscopy during charging and discharging processes. In the lithiation process, as the lithium content increases, the S-S bonds are observed the decrease of peak intensity at first, and the C-S bonds are observed to decrease after, indicating lithium ions react with S-S bonds prior to the C-S bonds. This observation is supported by the dissociation energy of C-S bond (272 kJmol-1) and S-S bond (251 kJmol-1) as well. In the delithiation process, the peaks of C-S and S-S have slightly increased to the end of charge. However, the intensity is not as intensive as the initial SPAN, which may indicate the formation of nano-sized sulfur in PAN backbone. The reaction mechanism of SPAN during the lithiation/delithiation process is further discussed and understood in this work, which could contribute to design and enhance better sulfur-polymer based material for lithium-ion battery use.

Ab initiostudy of anisotropic mechanical properties of LiCoO2 during lithium intercalation and deintercalation process

The mechanical properties of LixCoO2 under various Li concentrations and associated anisotropy have been systematically studied using the first principles method. During the lithium intercalation process, the Young's modulus, bulk modulus, shear modulus, and ultimate strength increase with increasing lithium concentration. Strong anisotropy of mechanical properties between a-axis and c-axis in LixCoO2 is identified at low lithium concentrations, and the anisotropy decreases with increasing lithium concentration. The observed lithium concentration dependence and anisotropy are explained by analyzing the charge transfer using Bader charge analysis, bond order analysis, and bond strength by investigating partial density of states and charge density difference. With the decrease of Li concentration, the charge depletion in the bonding regions increases, indicating a weaker Co-O bond strength. Additionally, the Young's modulus, bulk modulus, shear modulus, and toughness are obtained by simulating ab initio tensile tests. From the simulated stress-strain curves, LixCoO2 shows the highest toughness, which is in contraction with Pugh criterion prediction based on elastic properties only.

Effects of Excess Lithium on Microstructure and Magnetic Properties of Microwave Li-Zn Ferrites

Lithium zinc (Li0.35+xZn0.3Mn0.08Fe2.27O4±δ) ferrites with excess lithium concentration x varying from 0 to 0.08 in steps of 0.02 were prepared by conventional oxide ceramic method. XRD patterns confirm the spinel structure of Li0.35+xZn0.3Mn0.08Fe2.27O4±δ ferrites. According to the results of SEM photograph, excess lithium can compensate the volatilization of lithium during the sintering process and an appropriate amount of excess lithium is found to decrease the material porosity obviously, which improves the comprehensive performance of Li-Zn ferrites effectively. As the excess lithium concentration increases, the grain growth is restricted and the average grain size decreases. The bulk density d and saturation magnetization Ms increase firstly and then decrease with the increase of Li-excess x. In the meanwhile, the coercive force Hc shows a gradually increasing trend from 190A/m to 1036A/m, and the resistivity ρ has a monotonically increase due to the decrease of Fe2+ irons.

Fracture Toughness Characterization of Lithiated Germanium as an Anode Material for Lithium-Ion Batteries

Germanium (Ge) is a promising candidate anode material for next-generation, high-performance lithium-ion batteries. Despite its apparent promise, the mechanical properties of lithiated Ge including its fracture characteristic are largely unknown. In this paper, we report the first experimental measurement of the fracture toughness of lithiated Ge using an in-house developed nanoindentation system. The fracture toughness of lithiated Ge is found to increase monotonically with increasing lithium content, indicating a brittle-to-ductile transition of lithiated Ge as lithiation proceeds. We also compare the fracture energy of lithiated Ge with that of lithiated Si and show that, despite a slightly lower fracture energy of Ge than that of Si in the unlithiated state, Ge possesses much higher fracture resistance than Si in the lithiated state. These findings suggest that Ge anodes are intrinsically more resistant to fracture than their Si counterparts, thereby offering substantial potential for the development of durable, high-capacity, and high-rate lithium-ion batteries. The quantitative results from this work provide fundamental insights for developing new electrode materials and help to enable predictive modeling of high-performance lithium-ion batteries.

Brittle versus ductile fracture mechanism transition in amorphous lithiated silicon: From intrinsic nanoscale cavitation to shear banding

Large-scale atomistic simulations were performed to investigate the fracture behaviors of amorphous lithiated silicon. The simulation results revealed that as the lithium concentration increases, there exists a transition in fracture mechanism from intrinsic nanoscale cavitation to extensive shear banding ahead of the crack tip. It is shown that the observed fracture-mechanism transition can be understood from the changing ratio between critical stresses for cavitation and plastic yield under increasing lithium content. Furthermore, we investigated the mechanistic details of cavitation (i.e. growth of nanovoids) in amorphous lithiated silicon using fully three-dimensional atomistic simulations. It was revealed that in a low lithium concentration environment, an initial void grows heterogeneously by merging with neighboring nucleated voids. However, at high lithium concentrations, the initial void continues to grow in a homogeneous mode. These atomistic mechanisms provide a fundamental understanding of how silicon anodes in lithium-ion batteries fracture during lithiation.

A Phosphonium Bis(fluorosulfonyl)Imide-Based Ionic Liquid Electrolyte for Lithium Batteries: Tailoring Composition and Performance

The electrolyte is one of the key components of an energy storage device required to achieve high reliability and safety as well as high energy density. Lithium batteries have become one of the most common technologies for portable electronics and are making their way into electric vehicles and stationary storage. The interaction of a phosphonium-based room temperature ionic liquid (RTIL) with a lithium salt, lithium bis(fluorosulfonyl)imide, as a function of temperature and concentration has been evaluated and correlated with the mechanism of lithium transport. The formulated system could be a potential safe electrolyte for lithium batteries to meet the challenges presented by emerging battery technologies. We have found that the highly conductive and fluid phosphonium ionic liquid based on FSI anion gives excellent performance for lithium batteries, particularly for electrolytes containing higher lithium salt concentrations. The relationship between the physical properties and the mobility of the species present in solution has also been investigated. A combination of differential scanning calorimetry (DSC), electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), nuclear magnetic resonance (NMR) and X-Ray Photoelectron (XPS) spectroscopy techniques were used to characterise these novel electrolytes. Impedance spectroscopy measurements established that the addition of lithium bis(fluorosulfonyl)imide to the ionic liquid decreased the ionic conductivity over a range of temperatures (from -20 to 120°C) and this was related to an increase of the dynamic viscosity. Interestingly, the mechanism of lithium transport is dependent on the lithium concentration. It is also evident from EIS and NMR that the mobility of the species in solution is dependent on lithium salt concentration, and this impacts the electrolyte transport properties and mechanism. These data give an insight into the fluidity of the species when introducing lithium into the system. In terms of lithium electrodeposition, cyclic voltammetry (CV) is a powerful tool to better understand the electrochemical stability of lithium metal in the electrolyte to demonstrate the viability of using a lithium based anode in a battery. Cyclic voltammetry measurements showed that reversible electrodeposition of lithium at a nickel electrode could be observed at very high lithium salt concentrations (up to 3.8 mol.kg-1 of lithium salt) at 25°C. An increase of lithium concentration also revealed an improved efficiency and electrochemical stability at more negative potentials. These data provided an insight into the fundamental mechanism of lithium transport. The results suggest that the binary systems behave as a potential electrolyte including improved safety and stability.

Electrochemical Stiffness Measurements of Graphite Anodes for Li-Ion Batterie

We report on measurement of the electrochemical stiffness of the graphite anodes during Li exchange in Li-ion batteries. Graphite is the most common anode material used in commercial Li-ion batteries. During lithiation and delithiation of the graphite anodes, Li-graphite intercalation compounds with varying Li content (Li x C6, 0 ≤ x ≤ 1), and graphene layer spacing are formed. Hence, Li intercalation and de-intercalation causes considerable mechanical changes in the whole electrode. We use curvature bending measurements to monitor stress changes in a thin graphite electrode constrained on an inert, rigid substrate. In a separate experiment, we employ digital image correlation to track strain changes in a free-standing, unconstrained graphite electrode. Combining in-situstress and strain analyses enables us to extract the potential-dependent stiffness of the graphite anodes during lithiation-delithiation cycles. As expected, graphite anodes develop compressive stress during lithiation (ca. 10 MPa). The compressive stress is removed during delithiation. Strain response also corresponds with the Li deposition and removal, as graphite anodes expand during lithiation (ca. 1.5 % linear strain) and contract over delithiation. The electrode exhibits an initially stiff response at high potentials and low lithium contents, and then gradually softens during early formation of dilute stage I of the Li-graphite intercalation compound. As the potential is lowered and lithium content increases, several oscillations in the stiffness are observed, which correspond with the phase transitions during different stages of graphite lithiation. The evolution of stress, strain and stiffness data provides quantitative information on the coupled electro-chemo-mechanical response of the battery electrodes and insight on material strategies to increase battery reliability.

Lithium Potentiates Epithelial–Mesenchymal Transition in the Kidney through Induction of Matrix Metallopeptidase‐9

Lithium is a common therapeutic agent that is used to effectively treat patients with various mood disorders. Unfortunately there are many renal side effects of lithium therapy, including tubular atrophy and chronic interstitial fibrosis, which are not fully understood. To identify the intracellular signaling cascades that cause the proliferative action of lithium in the inner medullary collecting duct (IMCD), mIMCD3 cells were incubated with increasing concentrations of lithium chloride for 48 h. We found that lithium inhibited glycogen synthase kinase 3β (GSK‐3β) activity through serine‐9 phosphorylation in a dose responsive manner. Lithium inhibition of GSK‐3β induced ERK phosphorylation a concentration‐dependent manner. Both GSK‐3β and ERK are known to be involved in a variety of biological processes and are suggested to be key in the proliferative and antiapoptotic actions of lithium in the renal collecting duct. A reported downstream target of these kinases is matrix metallopeptidase 9 (MMP‐9), an enzyme that induces tubular cell epithelial‐mesenchymal transition (EMT) and therefore a major contributor to renal fibrosis. We found that protein abundance of MMP9 was elevated with increasing lithium concentrations in mIMCD3 cells. These results suggest that lithium inactivation of GSK‐3β potentiates EMT through ERK induction of MMP‐9 in the collecting duct.