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A hybrid electrolyte composed of a high-concentration electrolyte made of dimethyl carbonate and lithium bis(fluorosulfonyl)imide and lithium exchanged faujasite-type zeolite exhibits solidification of the electrolyte with high ionic conductivity and excellent contact properties with a lithium metal anode and an olivine-type LiFePO4 cathode. The assembled battery showed excellent cyclability for at least 100 cycles at a charge rate of 1 C at 60 °C with a discharge capacity retention of 98.6 % and high coulombic efficiency.

CO2 evolution is involved in various main and side reactions of electrochemical systems, such as carbon corrosion reactions and alcohol oxidation reactions. Differential electrochemical mass spectroscopy (DEMS) has been intensively applied to analyze the partial current of the CO2 evolution reaction in acidic and neutral electrolyte solutions. However, the quantitative analysis of the CO2 evolution reaction in alkaline electrolyte solutions has not been successful when catalyst-loaded carbon electrodes were applied, due to the high solubility of CO2 in the electrolyte. In this study, we develop a new DEMS system combining microreactor and ion exchange membrane to quantitatively analyze CO2 evolution reactions of catalyst-loaded carbon electrodes in alkaline electrolyte solutions. The calibration constant, which correlates the mass signal of m/z = 44 to the partial current of the CO2 evolution reaction, is successfully obtained from the Faradaic current and the mass signal of CO stripping voltammetry. We analyze carbon corrosion reactions of Pt and metal oxide-loaded carbon electrodes to demonstrate the effectiveness of the constructed system. The corrosion behavior of the Pt-loaded carbon is similar to that in the acidic electrolytes except for the onset potential of the carbon corrosion. La0.6Ca0.4CoO3 and Ca2FeCoO5 show electrochemical carbon corrosion activity, while La0.4Sr0.6MnO3 does not show distinct electrochemical carbon corrosion activity.

The mixing process of electrode-slurry plays an important role in the electrode performance of lithium-ion batteries (LIBs). The dispersion state of conductive materials, such as acetylene black (AB), in the electrode-slurry directly influences the electronic conductivity in the composite electrodes. In this study, the relation between the mixing process of electrode-slurry and the internal resistance of the composite electrode was investigated in combination with the characterization of the electrode-slurries by the rheological analysis and the alternating current (AC) impedance spectroscopy. Some of the electrode-slurries showed higher value and gentler slope of the dynamic storage modulus in the low-angular-frequency region and higher thixotropic index than the others depending on the way of the mixing process and the AB content, agreeing with the low electronic volume resistivities of the corresponding composite electrodes and the electrode-slurries, which indicates the AB network growth. The results suggested that the low-viscosity state when AB and active electrode material are mixed contributes to the dispersive AB network.

Solid electrolyte interphase (SEI) layer that forms on the graphite negative electrodes of lithium-ion batteries (LIBs) has a crucial role in inhibiting the excess decomposition of electrolyte solutions. While this passivating ability is essential for improving the durability of LIBs, the relationship between the passivating ability and the surface structure of the graphite is not yet fully understood. In this study, we investigate the solvent co-intercalation behavior in the presence of SEI layers formed on various types of graphite surface structures. The amount of edge sites on each graphite sample is determined using electric double layer capacitance. The co-intercalation reactions of untreated, ethylene-carbonate-treated, and vinylene-carbonate-treated graphite samples in dimethoxyethane-based electrolyte solutions are compared. The co-intercalation reactions commence at approximately 1 V vs. Li/Li+ for all untreated samples, but the onset potentials are lowered by the presence of SEI layers, and the extent of this lowering depends on the sample. The SEI layer formed on the edge-rich surface effectively suppresses the co-intercalation reaction, and the additive is also more effective for the edge-rich sample.

Abstract Background Kimura’s disease (KD) is a rare chronic inflammatory disease of unknown etiology. Clinically, KD is characterized by nodular subcutaneous masses, that are typically localized to the neck and head. Involvement of the lacrimal glands and limbs is uncommon and seldom reported. Case presentation We report a case of a 4-year-old Japanese boy presenting with bilateral upper eyelid swelling with nodular subcutaneous lesions and peripheral eosinophilia. Based on clinical, histopathological, and laboratory findings, the patient was diagnosed with KD. An itchy subcutaneous mass on the left arm developed at the age of 14 years. Treatment with steroids was effective. However, as the steroids were tapered after the patient developed side effects, the masses relapsed within a few months. Treatment with cyclosporine A was then initiated, which led to an improvement of clinical features and serial levels of cytokines. Conclusions We report a rare case of KD with a peculiar clinical presentation. The patient responded well to treatment with cyclosporine A.

Abstract Background The association of hypertension with congenital renal hypoplasia has been established. We report a case of an infant who underwent nephrectomy for hypertension. Case presentation Magnetic resonance imaging for the mother revealed fetal renal masses, and fetal multicystic dysplastic kidney was suspected. Following birth, the baby developed hypertension. Numerous investigations revealed that the left kidney was non-functional, and she was initiated on benazepril hydrochloride. However, because the drug response was poor, the left kidney was removed at the age of 7 months. Examination of the renal specimen revealed abrupt transition from normal to atrophic cortex with lobar atrophy and cysts. Tubular atrophy, marked abnormal blood vessels with wall thickening, gathered immature glomeruli, and parenchymal destruction were observed. Renin was partially localized in the proximal tubules and the parietal epithelium of the Bowman’s capsule in the immature glomeruli. We speculated that an abnormal vascular structure and irregular renin localizations may be the cause of hypertension. Serum renin and aldosterone levels gradually reduced post-surgery, reaching normal levels on the 90th postoperative day. A long follow-up is needed due to the possibility of the child developing hypertension in the future. Conclusion This is a case of an infant with MCDK, which discusses the clinicopathological features based on the pathophysiological analysis, including renin evaluation.

Degradation of LiMn2O4 in LiPF6-based electrolyte solution is complicated due to the influence of PF6− anion. Decomposition of PF6− anion accelerates both of dissolution of manganese ion and surface-film formation. In this study, surface states of LiMn2O4 thin-film electrodes in LiPF6/propylene carbonate (PC) derived from the surface-film formation were investigated using redox reaction of ferrocene and spectroscopic analyses. The spectroscopic analyses suggested that properties of the surface film depended the operation temperature (30 °C and 55 °C); a thinner surface film composed of LiF and PC decomposition products formed on LiMn2O4 at 30 °C and a thicker surface film was formed at 55 °C. The redox reaction of ferrocene clearly showed that LiMn2O4 was completely passivated at 30 °C, while it was partially passivated at 55 °C, indicating the surface film formed at 55 °C was not compact and LiMn2O4 was exposed to the electrolyte solution. It was one of the causes of the rapid degradation of LiMn2O4 at elevated temperatures in LiPF6-based electrolyte solution.

The performance of the graphite anode of lithium-ion batteries is greatly affected by the solid electrolyte interphase (SEI) generated at the first charge. However, there are few studies on the kinetics of the lithium-ion intercalation/de-intercalation reaction in graphite to investigate the effect of SEI. In this study, the correlation between the interfacial lithium-ion transfer resistance (Rct) and the double layer capacitance (Cdl) of graphite composite electrodes coated with various SEIs was investigated. It was found that the value of 1/RctCdl was different for each SEI, that is, the frequency (or rate) of intercalation and de-intercalation of lithium ions into graphite was different for each SEI. The activation energy of Rct was almost the same for all the electrolyte solutions. These results indicate that the pre-exponential factor of the Arrhenius equation governing the rate of interfacial ion transfer in a practical graphite anode is dependent on the nature of SEI.

Abstract Background IgA deficiency associated with glomerulonephritis is rare. In particular, there is no prior report regarding the association between IgA deficiency and membranoproliferative glomerulonephritis (MPGN) in children. Herein, we describe the case of a 5-year-old girl with selective IgA deficiency and MPGN. Case presentation The patient presented with persisting urinary abnormality and hypocomplementemia following a group A treptococcal infection. Renal biopsy revealed the presence of diffuse mesangial hypercellularity, endocapillary proliferation, and focal thickening of the walls of the glomerular capillaries using light microscopy, with IgG and moderate C3 deposits observed using immunofluorescence. Electron microscopy images revealed nodular deposits in the subendothelial areas, with hump-shaped subepithelial deposits. The pathological diagnosis was confirmed as MPGN. Treatment using oral prednisolone (PSL), mizoribine (MZR), and angiotensin-converting enzyme inhibitors reduced the proteinuria. The PSL dose was gradually tapered, with the low dose of PSL and MZR continued for 4 years. Histological findings were improved on repeated renal biopsy, and PSL and MZR administration was discontinued. Conclusions We report a rare case of MPGN related to a streptococcal infection in a child. The clinical presentation included selective IgAD, with several pathological findings and a clinical course typical of glomerulopathy. The patient was successfully treated using multidrug therapy.

Here, highly concentrated sodium bis(fluorosulfonyl)amide (NaFSA) aqueous electrolytes were examined for the aqueous electrolytes of electric double-layer capacitors with wide potential window. Firstly, fundamental properties of electrolytes were investigated using conductivity measurements and Raman spectroscopy. During cyclic voltammetry of activated carbon electrodes, aluminum corrosion was observed for positive electrode side. After current collectors of positive electrodes were changed to titanium, capacitor reactions were confirmed for both of positive electrode and negative electrode sides in NaFSA aqueous electrolytes. In addition, resistances of activated carbon electrodes in NaFSA aqueous electrolytes were smaller than those in LiTFSA aqueous electrolytes.

Abstract Background: The pathological findings of tonsils in IgA nephropathy include the expansion of T-cell nodules around lymphoid follicles and abnormal reticulation of the crypt epithelium in contrast to chronic tonsillitis. Recently, several studies have reported that regulatory T cells play an important role in the maintenance of self-tolerance, an abnormality that is involved in the onset of nephrotic syndrome (NS). We encountered a patient of 28-year-old male with frequently relapsing nephrotic syndrome (FRNS) and chronic tonsillitis whose tonsils demonstrated pathological findings similar to those of IgA nephropathy. Case presentation A patient had developed NS at the age of 5 years, and was pathologically diagnosed with minimal change disease (MCD), for which he received various immunosuppressive agents as treatment for recurrence. Because tonsillitis often triggers the recurrence of NS, a tonsillectomy was performed for chronic tonsillitis at the age of 25 years. Immunohistochemical staining of his tonsils showed the expansion of CD4 positive lymphocytes around the lymphoid follicles and abnormal reticulation of the crypt epithelium. The number of peripheral blood CD4+CD25+ regulatory T cells increased, and the frequency of relapses decreased after tonsillectomy. Conclusion A similar self-tolerance abnormality exists in NS and IgA nephropathy; therefore, tonsillectomy might become a novel therapeutic approach for FRNS to redress the unbalanced self-tolerance and to remove the tonsillar focal infection. Further studies are necessary to verify the clinical efficiency of tonsillectomy for FRNS with recurrent episodes triggered by tonsillitis.

Graphite intercalation compounds of bis(fluorosulfonyl)amide (FSA-GICs) are electrochemically synthesized in a highly concentrated aqueous solution. While only water decomposition occurs at the graphite electrode in a dilute aqueous solution (1 mol kg−1 NaFSA), redox peaks clearly appear in a highly concentrated aqueous solution (19 mol kg−1 NaFSA). Under the application of a constant current, the electrode potential reaches 1.7 V (vs. Ag/AgCl), which is far beyond the upper limit of the potential window, in 19 mol kg−1 NaFSA aq., and the formation of FSA-GIC is confirmed by X-ray diffraction patterns. Acceptor-type GICs using organic anions are observed for the first time in highly concentrated aqueous solutions of NaFSA. Keywords: Concentrated aqueous solutions, Graphite intercalation compounds, Water decomposition, Potential window

This comprehensive paper, Electrode Potentials Part 2, is a continuation of Electrode Potentials Part 1: Fundamentals and Aqueous Systems. Determining the electrode potential is crucial for understanding the nature of the electrochemical properties of materials or systems; however, an accurate evaluation of the potential of a target electrode has always been a challenge. The electrode potential can be used to predict the reaction mechanisms in electrochemistry and can be directly applied to the study of electrochemical applications. This paper introduces the methodologies and strategies for measuring electrode potentials in nonaqueous and solid-state electrolytes, including organic solvent electrolytes, ionic liquid electrolytes, and oxide and sulfide solid electrolytes. Experimental details are described for basic to state-of-the-art strategies, focusing on practical methods and know-how.

Electrochemistry deals with the interrelationship between electrical and chemical energy. Various potentials appear in electrochemistry and pertain to one another in practical cells. Understanding the electrode potential is an important step in acquiring basic knowledge of electrochemistry and extending it to specific applications. This comprehensive paper outlines the fundamentals and related subjects of electrode potentials, including electrochemical cells and liquid junction potentials. Aqueous solution systems are ideal for connecting the theoretical background of electrode potentials to practical electrochemical measurements. Accordingly, the basic electrode chemistry in aqueous systems is described in this paper, as well as several advanced concepts introduced in recent studies.

The characteristics of the interface between Ni-rich cathode materials and carbonate-based electrolytes are crucial for stability in charge-discharge cycles. In this study, we used tris(trimethylsilyl)phosphite (TMSPi) as an additive for film formation and investigated the properties of the layer formed on a LiNi0.6Co0.2Mn0.2O2 (NCM622) thin-film electrode. This layer can act as a barrier to mitigate the underlying attack at the oxygen sites of the layered Ni-rich structure. Moreover, this layer mainly consists of Li-rich organic components, leading to a decreased activation energy with a rapid Li-ion transfer process.

Rotating disk voltammograms of electrocatalytic reactions were often analyzed on a model of the totally irreversible reaction. The problem with the conventional method is pointed out, and the validity of an analysis method on a model of the electrocatalytic reaction is demonstrated for oxygen-reduction reaction (ORR) as an example. Rotating disk voltammograms of ORRs sometimes show gradual change in the limiting current region called residual slope. The phenomenon has been explained on a random distribution model in which the catalytic sites communicate in long-range electron transfer with the electronic conductors that locate at distances (z), and are uniformly distributed with respect to z. Observed data of an ORR were well reproduced by non-linear least squares analysis on the random distribution model. The result of the analysis is briefly discussed.

Steady-state experiments are often conducted to understand complicated cases in chemistry, since the kinetics does not have a time valuable and allows simple modeling of the reactions. The reciprocal of the overall rate of sequential steady-state reactions is often given in the reciprocal sum formula: sum of the reciprocals of the rates of the hypothetical rate-limiting processes at the individual stages. In this paper, the reciprocal sum relationship is generalized for sequential multi-step steady-state reactions, and the importance and usefulness of the concept is shown by applying it to describe several typical steady-state systems in enzyme reactions and voltammetry using rotating disk- and ultramicro-electrodes.

All-solid-state lithium-ion batteries that use sulfide solid electrolytes have attracted much attention due to their high safety and wide electrochemical window. In this study, highly oriented pyrolytic graphite (HOPG) and 75Li2S-25P2S5 (mol%) glass were used as a model graphite negative electrode and a sulfide solid electrolyte, respectively. Interfacial lithium-ion transfer between 75Li2S-25P2S5 glass and the HOPG electrode was studied by AC impedance spectroscopy measurements. The activation energy of the interfacial lithium-ion transfer was estimated to be around 37 kJ mol−1, which was much smaller than that at the interface between organic liquid electrolytes and HOPG electrode, indicating that the lithium-ion transfer at the interface between 75Li2S-25P2S5 glass and HOPG electrode proceeded quite rapidly. Furthermore, surface deposition of TiO2 and surface oxidation on HOPG electrodes were performed using the atomic layer deposition (ALD) method. Interfacial lithium-ion transfer between 75Li2S-25P2S5 glass and ALD-modified-HOPG electrodes was also investigated. The activation energies of the interfacial lithium-ion transfer were slightly higher than that of HOPG, but the resistance of the charge-transfer process was lower, indicating that the affinity of the HOPG electrode for the glass electrolyte was improved by surface modification.

The reaction kinetics of electrochemical lithiation/delithiation in a composite consisting of black phosphorus and cup-stacked carbon nanotube (BP-CSCNT) were investigated. Two semicircles were observed in Nyquist plots at the high and low frequency regions, which were attributed to the resistance of lithium-ion transport through the surface film and the resistance of the alloying/dealloying reaction (charge-transfer resistance), respectively. The activation energy using the charge transfer reaction was evaluated from the temperature-dependence of the interfacial conductivity. Even with the use of ethylene carbonate-based and propylene carbonate electrolytes, the activation energy was calculated to be 25–26 kJ mol−1, which is much smaller than that obtained with graphite electrodes and cathode materials. These results indicate that the ionic charge transfer process in BP-CSCNT composite electrodes is not coupled with the desolvation process and suggest that the charge transfer in BP-CSCNT is exceptionally fast compared to that in other insertion materials.

Spherical LiNi0.5Mn1.5O4 particles co-doped with lanthanum (La) and sulfur (S) were synthesized by a facile co-precipitation assisted solid-state annealing method with stable oxysulfide La2O2S (x = 0, 0.3, 0.5, 0.7, 1.0, and 1.2 at%) as a dopant. The prepared composite materials exhibited a slight shrinkage of lattice parameters without any impurity phase under x ≤ 0.7 at%, and the Ni/Mn disordered arrangement in the spinel lattice increased with an increase in the ratio of dopants, as confirmed by X-ray diffraction and Raman spectroscopy. X-ray photoelectron spectroscopy and electrochemical measurements also clearly indicated that the residual Mn3+ in the cubic lattice could be effectively eliminated with the use of La2O2S dopants. The composite materials showed outstanding rate and cycling performance compared with those of the pristine material. Specifically, the material doped with 0.5 at% La2O2S showed a high reversible capacity of 115.9 mAh g−1 at 10 C, and a remarkable cycling performance of 109.2 mAh g−1 even after 200 cycles. All of these extraordinary performances were attributed to the synergistic effects of La and S in the spinel structure, which induce a suitable pathway for lithium ion and a robust architecture during the electrochemical assessment.

Impact of hydrogen peroxide on carbon corrosion is investigated by immersion tests of catalyst-deposited highly oriented pyrolytic graphite (HOPG) samples to an aqueous solution of 1.0 mol dm−3 KOH + 5 mmol dm−3 H2O2. The surfaces of the HOPG samples are observed with field-emission scanning electron microscopy and X-ray photoelectron spectroscopy. HOPG without catalyst shows almost no morphological change while the distribution of C-O and C=O functional groups increases. In contrast, Pt-loaded HOPG exhibits the formation of scars and COO functional groups, which shows a relatively severe carbon corrosion reaction resulting in CO32− formation. Since the Pt-loaded HOPG after the immersion test to 0.5 mol dm−3 H2SO4 + 5 mmol dm−3 H2O2 shows much smaller scars, it can be concluded that hydrogen peroxide corrodes Pt-loaded carbon more severely in the alkaline electrolyte solution than the acid electrolyte solution. Ag-loaded HOPG also shows the scars, while the sizes of scars are much smaller than those on the Pt-loaded HOPG. In contrast, MnOx and CoOx-loaded HOPGs exhibit no scar and minor oxygen-containing functional groups than the HOPG without catalyst, whereas MnOx and CoOx-loaded HOPGs shows larger scars than Pt and Ag-loaded HOPGs after electrochemical carbon corrosion test.

A lithium-rich layered structure in lithium-ion batteries (LIBs) has attracted much attention due to its high capacity of over 250 mAh g−1 after activation. This could satisfy the requirements of next-generation energy-storage devices. However, a spinel-like impurity phase that forms from the pristine layered structure during cycling is considered to be harmful to the structure stability and Li+ mobility, resulting in undesired electrochemical performance. In this study, nanorod-like Li1.2Ni0.2Mn0.6O2 with a three-dimensional architecture was synthesized by evaporative-crystallization with as-prepared nano-MnO2 as a hard template. The structure stability and Li+ mobility of the nanorod-like Li1.2Ni0.2Mn0.6O2 was improved by the addition of an appropriate molar ratios of (La, Zr) co-dopants. This combination exhibited outstanding capacity retention of 80.9 % with a stable discharge capacity of 102 mAh g−1 after 300 cycles under a high current density of 1000 mA g−1 (corresponding to 5 C). This study suggests that the use of a multi-prong strategy that combines morphology control and co-doping should be an effective method for improving the high-rate performance of Li-rich materials.