Manganese Borate Research Articles

Amorphous Heterostructure Derived from Divalent Manganese Borate for Ultrastable and Ultrafast Aqueous Zinc Ion Storage.

Aqueous zinc-manganese (Zn-Mn) batteries have promising potential in large-scale energy storage applications since they are highly safe, environment-friendly, and low-cost. However, the practicality of Mn-based materials is plagued by their structural collapse and uncertain energy storage mechanism upon cycling. Herein, this work designs an amorphous manganese borate (a-MnBOx ) material via disordered coordination to alleviate the above issues and improve the electrochemical performance of Zn-Mn batteries. The unique physicochemical characteristic of a-MnBOx enables the inner a-MnBOx to serve as a robust framework in the initial energy storage process. Additionally, the amorphous manganese dioxide, amorphous Znx MnO(OH)2 , and Zn4 SO4 (OH)6 ·4H2 O active components form on the surface of a-MnBOx during the charge/discharge process. The detailed in situ/ex situ characterization demonstrates that the heterostructure of the inner a-MnBOx and surface multicomponent phases endows two energy storage modes (Zn2+ /H+ intercalation/deintercalation process and reversible conversion mechanism between the Znx MnO(OH)2 and Zn4 SO4 (OH)6 ·4H2 O) phases). Therefore, the obtained Zn//a-MnBOx battery exhibits a high specific capacity of 360.4 mAh g-1 , a high energy density of 484.2Wh kg-1 , and impressive cycling stability (97.0% capacity retention after 10000 cycles). This finding on a-MnBOx with a dual-energy storage mechanism provides new opportunities for developing high-performance aqueous Zn-Mn batteries.

Fabrication of manganese borate/iron carbide encapsulated in nitrogen and boron co-doped carbon nanowires as the accelerated alkaline full water splitting bi-functional electrocatalysts

With high prices of precious metals (such as platinum, iridium, and ruthenium) and transition metals (such as cobalt and nickel), the design of high-efficiency and low-cost non-precious-metal-based catalysts using iron (Fe) and manganese (Mn) metals for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) are critical for commercial applications of water splitting devices. In the study, without using any template or surfactant, we successfully designed novel cross-linked manganese borate (Mn3(BO3)2) and iron carbide (Fe3C) embedded into boron (B) and nitrogen (N) co-doped three-dimensional (3D) hierarchically meso/macroporous carbon nanowires (denoted as FexMny@BN-PCFs). Electrochemical test results showed that the HER and OER catalytic activities of Fe1Mn1@BN-PCFs were close to those of 20 wt% Pt/C and RuO2. For full water splitting, (-) Fe1Mn1@BN-PCFs||Fe1Mn1@BN-PCF (+) cell achieved a current density of 10 mA cm−2 at a cell voltage of 1.622 V, which was 14.2 mV larger than that of (-) 20 wt% Pt/C||RuO2 (+) benchmark. The synergistic effect of 3D hierarchically meso/macroporous architectures, excellent charge transport capacity, and abundant active centers (cross-linked Mn3(BO3)2/Fe3C@BNC, BC3, pyridinic-N, MNC, and graphitic-N) enhanced the water splitting catalytic activity of Fe1Mn1@BN-PCFs. The (-) Fe1Mn1@BN-PCFs||Fe1Mn1@BN-PCF (+) cell exhibited excellent stability owing to the superior structural and chemical stabilities of 3D hierarchically porous Fe1Mn1@BN-PCFs.

Gamma-ray/neutron shielding capacity and elastic moduli of MnO–K2O–B2O3 glasses co-doped with Er3+ ions

Gamma-ray/neutron shielding capacity and mechanical properties of erbium-doped potassium manganese borate glasses with the chemical form of (1 − x)MnO–29K2O–70B2O3–xEr2O3: x = 0–1 mol% coded as E0–E5 via bond compression model, XCOM software, and PHITS simulations have been investigated. The bulk modulus (KB.C) values increased from 90.19 for E0 glass sample with free Er2O3 to 101.24 GPa for E5 glass sample with Er2O3 = 1 mol%. The Young’s modulus (EB.C) increased from 102.68 GPa to 115.38 GPa, while the longitudinal modulus (LB.C) increased from 142.31 GPa to 159.81 GPa for E0–E5 glasses. Poisson’s ratio (σB.C) decreased from 0.310261 to 0.310065 with the increase of Er3+ ions in the investigated glasses. Hardness of E0–E5 glasses was increased from 4.96 GPa to 5.58 GPa. The mass attenuation coefficient (µ/ρ) values were the highest at the least energy of 0.284 MeV with values of 0.1080, 0.1096, 0.1113, 0.1129, 0.1145, and 0.1161 cm2 g−1 for E0, E1, E2, E3, E4, and E5, respectively. Moreover, radiation protection efficiency (RPE) of the E0–E5 glasses was estimated using PHITS simulation code. The highest RPE was observed for E5 glass with a thickness of 5 cm. Finally, the neutron shielding capacity of E0–E5 glasses was evaluated in terms of the fast neutron removal cross section (FNRCS). The values of FNRCS increased by adding Er2O3 content and a sharp increase was observed at xEr2O3: x = 0.8 mol%. Generally, one can conclude that the E5 glass sample with the highest Er2O3 (1 mol%) concentration is the best sample as radiation shield among all the studied glasses.

Thermal dehydration kinetics of non-crystalline manganese borate

In this study, non-crystalline manganese tetrahydric orthoborate (MnH 4 (BO 3 ) 2 ) is synthesized by using MnSO 4 .H 2 O, NaOH and H 3 BO 3 via hydrothermal method. The characterizations of the synthesized compounds are conducted using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). Thermal dehydration studies are conducted using the thermogravimetric analysis (DTG/TG). From the XRD result, amorphous manganese borate is synthesized and the FTIR spectrum shows characteristic borate vibrations in the IR region. A uniform particle size distribution at the micron scale with partially agglomerated is observed from SEM images. The thermogravimetric results dehydration process occurs between the temperatures of 40 – 270°C in one-step reaction with average weight loss of 19.26%. Average activation energies ware determined by using the non-isothermal kinetics methods of Coats-Redfern, Horowitz-Metzger and Van-Krevelen and found as 37.83, 46.54 and 37.88 kJ/mol, respectively.

Structure and Properties of the Non‐Centrosymmetric Manganese(II) Borate Mn5(BO3)3OH

The rose‐colored compound Mn5(BO3)3OH was synthesized under high‐pressure/high‐temperature conditions of 2.5 GPa and 973 K in a Walker‐type multianvil press. Single‐crystal X‐ray structure determination yielded the non‐centrosymmetric monoclinic space group Pm (no. 6) with the lattice parameters a = 329.71(1), b = 1384.92(5), c = 902.37(3) pm, and β = 107.92(1)°. The presence of the hydroxide group is ascertained by vibrational spectroscopy. Magnetization experiments in the range from 300 to 14 K revealed paramagnetic behavior with antiferromagnetic ordering below 14 K and an effective magnetic moment of 12.2 µB per formula unit. The acentric nature of the material was verified by second harmonic generation measurements, yielding a considerably strong intensity (Isample/Iquartz = 11.14). Additionally, thermal investigations showed a several‐step transformation to Mn2OBO3 upon heating under air.

Structure-function of novel glasses for possibility as cathode of Li-ion battery: Lithium manganese borate glasses

Novel manganese-lithium borate glasses and its possibility as cathode materials in Li-ion battery are carefully investigated. The structure and phase formation of the prepared glasses, 0.3MnO2-0.7(LixBO2) with x = 0.25, 0.50, 0.75 and 1.00, were characterized using X-ray diffraction (XRD), X-ray absorption spectroscopy (XAS), and X-ray photoelectron spectroscopy (XPS) techniques. All XRD patterns present broad and no detectable peaks which confirmed purely amorphous phase. The CV curves exhibit pseudo-capacitance behavior indicating the mixed oxidation state of Mn2+/Mn3+ corresponding to Mn K-edge results measured by X-ray absorption near edge structure (XANES). The average Mn–O bonding distance was found in the range of 2.08–2.14 Å. SEM and TEM depict the existence of elements and confirm the glassy state of the obtained glass samples. The optical, magnetic, and electrochemical properties of these glasses have been also investigated. Paramagnetic behaviors are found for glass samples with x = 0.25, 0.50 and 0.75, respectively. Unlike other glass samples, the weak ferromagnetic was found at x = 1.0 composition. Interestingly, the highest specific capacitance value of 52 F g−1 is also obtained for 0.3MnO2-0.7(Li1.0BO2) glass suggesting a new promising glass electrode in future Li-ion battery.

Fine tuning of reactivity and structure of bis(σ)borate and borate complexes of manganese by systematic ligand variation

The complexes with fac-[M(CO)3]+ units of group-7 metals are interesting synthons for the development of target-specific drugs. Therefore, thermolysis reaction of Re2(CO)10 with various borate ligands have been investigated as a possible route to isolate bis(σ)borate complexes of rhenium. The reaction of trihydrobis(benzothiazol-2-yl)amideborate, Na[(H3B)bbza] (bbza = bis(benzothiazol-2-yl)amine) with Re2(CO)10 led to the formation of distorted octahedral rhenium complexes [(CO)2Re{N(C7H4NS)2}2], 1 and [(CO)2Re{N(C7H4NS)2}{C6H4N(Me)O}], 2. In order to increase the library of complexes containing fac-{M(CO)3}+ moieties as well as to check the lability of the metal–carbonyl bond, reactivity of manganese borate complexes [Mn(CO)3(μ-H)2BHNCSC6H4(NR)], 3 (R = NCSC6H4) and [Mn(CO)3{κ3-S,S′,H-H2B(mbz)2}], 6 (mbz = 2-mercapto-benzothiazolyl) with different ligands were carried out. Photolysis of 3 with excess phosphine ligands (PPh2Me or PMe2Ph) yielded manganese phosphine complexes [Mn(CO)2(PL2L′)2{N(C7H4NS)2}], (4a: L = Ph, L′ = Me; 4b: L = Me, L′ = Ph). Interestingly, the reaction of 3 with tBuNC yielded mono/bis(tBuNC)-substituted manganese borate complexes [Mn(μ-H)2(BHNCSC6H4)(NR)(CO)xLy], 5a–b (5a: x = 2, y = 1; 5b: x = 1; y = 2; L = tBuNC; R = NCSC6H4) and [Mn(μ-H)2BH{N(NCSC6H4)2}(CO)(tBuNC)2], 5c. Compounds 5b and 5c are structural isomers with a different coordination mode of the bbza ligand. Under similar reaction conditions, photolysis of 6 with PPh3 in toluene generated borate complex of manganese [Mn(CO2){κ3-S,S′,H-H2B(mbz)2}(PPh3)], 7. All the compounds were characterised by multi-nuclear NMR, IR spectroscopy and mass spectrometry. Density functional theory (DFT) calculations were carried out to investigate the bonding and electronic structures of these compounds.

Hierarchical growth of a novel Mn-Bi coupled BiVO4 arrays for enhanced photoelectrochemical water splitting

Oxygen evolving catalyst (OEC) is a critical determinant for the efficiency of photoelectrochemical (PEC) water splitting. Here we report an approach to depositing a novel manganese borate (Mn-Bi) OER catalyst on BiVO4 nanocone photoanode by photodeposition in sodium borate buffer solution containing Mn(II) ions. Due to the spontaneous photo-electric-field-enhancement effect at the vertically oriented BiVO4 nanocone structure, spherical Mn-Bi nanoparticle was selectively photodeposited at the apex of BiVO4 nanocone. Significant improvement of photocurrent was observed for the obtained hierarchical Mn-Bi/BiVO4 photoanode which could be ascribed to enhanced hole injection efficiency, especially in low bias region. It was observed that the injection efficiency of Mn-Bi/BiVO4 is 98% which gave a photocurrent of 0.94 mA/cm2 at 1.5 V vs. RHE.

Fabrication and characterization of electrospun single-crystal lead manganese borate nanofibers

Anhydrous borate compounds are important materials in optical applications as nonlinear optical materials (NLO), due to the presence of structural BxOy subunits. Herein, lead manganese borate (PbMnBO4) nanofibers have been firstly fabricated via a facile approach using a simple and inexpensive electrospinning technique. All of the synthesized samples were analyzed with X-Ray Diffractometer (XRD), Transmission Electron Microscope (TEM), Scanning Electron Microscope (SEM), Fourier Transform Infrared (FTIR), and Ultraviolet-visible Spectroscopy (UV–vis) method. In addition, they were thermally analyzed with Thermal Gravimetric and Differential Thermal Analyzer and TG-DTA diagrams were discussed in detail. All of the characterization results showed that the obtained PbMnBO4 nanostructures have nanofiber structures and good crystalline features. PbMnBO4 nanofiber synthesized for the first time and unprecedented in the literature is promising absorber materials for nonlinear optic applications.

Role of MnO in manganese–borate binary glass systems: a study on structure and thermal properties

Structural and thermal properties of \(x\hbox {MnO}-(100-x)\hbox {B}_{2}\hbox {O}_{3}\) (where \(x=40\), 50 and 60 mol%) glass samples have been investigated with the employment of various techniques. Fourier transform infrared spectroscopy results revealed the influence of MnO on glass matrix. Decrease of B–O bond-related band intensities has been observed. MnO addition was found to introduce broken [\(\hbox {BO}_{2}\hbox {O}^{-}\)]\(_{{n}}\) chains. Differential scanning calorimetry (DSC) measurements presented decreasing \(T_{\mathrm{g}}\) that indicates depolymerization of glass matrix in the considered compositional range. Moreover, thermal stability (TS) parameter has been evaluated using the DSC technique. It slightly decreased with MnO content. X-ray photoelectron spectroscopy results provided the evidence for \(\hbox {Mn}^{2+}\) and \(\hbox {Mn}^{3+}\) presence. Multiplet splitting, close to that of MnO, has been observed. It has been concluded that most of the manganese ions existed in the divalent state. Photoluminescence study revealed that manganese ions are tetragonally co-ordinated in a glassy matrix.

Structural and Elastic Studies of Strontium Doped Manganese Borate Glasses

Structural and Elastic Studies of Strontium Doped Manganese Borate Glasses

GROWTH OF THE EDIBLE MICROALGA ARTHROSPIRA PLATENSIS IN RELATION TO BORON SUPPLY

Arthrospira (Spirulina) platensis is an edible cyanobacterium that has been consumed worldwide as a nutrient source under the name spirulina. When preparing synthetic media for this microalga, boron is usually added to them. However, whereas boron is necessary for the N2-fixation-dependent growth of heterocystous cyanobacteria, boron requirement by A. platensis, which is non-heterocystous, has not yet been carefully examined. To examine the effect of boron on A. platensis, we prepared a boron-depleted medium in which borate concentration was below a detection limit (0.2 µM), as determined by the spectrophotometric quantitation with H-resorcinol. Using this boron-depleted medium, A. platensis NIES-39 was analyzed for changes in growth, dry biomass weight and the protein, chlorophyll a and C-phycocyanin contents. Experimental results showed that removal of boron from the growth medium had no detectable effect on them. A control experiment with a heterocystous cyanobacterium Anabaena sp. UTEX 2576 showed that the growth of this cyanobacterium was suppressed in a boron-depleted medium. These experiments demonstrated that boron was not required for the growth of A. platensis. Our results indicate that boron supply is not necessary for the propagation of A. platensis even in the regions where boron deficiency in the soil deteriorates the growth of common crops. Use of boron-free media would also be helpful to improve the reproducibility of sensitive physiological experiments such as metabolome analysis, because precipitation of the insoluble salt manganese borate, which may reduce the concentration of Mn2+ in the medium, does not occur in boron-free media.

Unusual stoichiometry control in the atomic layer deposition of manganese borate films from manganese bis(tris(pyrazolyl)borate) and ozone

The atomic layer deposition (ALD) of films with the approximate compositions Mn3(BO3)2 and CoB2O4 is described using MnTp2 or CoTp2 [Tp = tris(pyrazolyl)borate] with ozone. The solid state decomposition temperatures of MnTp2 and CoTp2 are ∼370 and ∼340 °C, respectively. Preparative-scale sublimations of MnTp2 and CoTp2 at 210 °C/0.05 Torr afforded >99% recoveries with <0.1% nonvolatile residues. Self-limited ALD growth was demonstrated at 325 °C for MnTp2 or CoTp2 with ozone as the coreactant. The growth rate for the manganese borate process was 0.19 Å/cycle within the ALD window of 300–350 °C. The growth rate for the cobalt borate process was 0.39–0.42 Å/cycle at 325 °C. X-ray diffraction of the as-deposited films indicated that they were amorphous. Atomic force microscopy of 35–36 nm thick manganese borate films grown within the 300–350 °C ALD window showed root mean square surface roughnesses of 0.4–0.6 nm. Film stoichiometries were assessed by x-ray photoelectron spectroscopy and time of flight-elastic recoil detection analysis. The differing film stoichiometries obtained from the very similar precursors MnTp2 and CoTp2 are proposed to arise from the oxidizing ability of the intermediate high valent manganese oxide layers and lack thereof for cobalt.

From 1-D to 3-D Li Intercalation: Channel-to-Channel Li Migration Facilitated By Antisite Disorder

Antisite defects, disorder between Li and other cations, are often observed in Li storage compounds synthesized at elevated temperature. In battery materials that have distinct one-dimensional (1-D) Li diffusion channels, preventing antisite formation is considered a good way to obtain desirable electrochemical properties by avoiding channel blockage, which can significantly disrupt Li transport. Thus, it is of critical importance to understand how the antisite modulates the overall Li kinetics in cathode materials. In this work, we investigate lithium manganese borate (LiMnBO3) as a model system in which Li diffuses along the c-axis of its monoclinic lattice. Although it has high theoretical capacity of 222 mAh/g, antisite defects limit the achievable capacity to half of its theoretical value. Our approach to address this limitation is to partially substitute Mn with Fe, which not only leads to immediate improvement in electrochemical properties but also increases the antisite defect concentration. By using ab initio computation and analyzing experimental results, we find that different antisite configurations can affect Li intercalation in different ways and, counter to intuition, channel blockage by the antisite defects is not always detrimental in 1-D materials. At certain conditions, Li migration occurs by channel crossover to detour the channel-blocking defect, and the basic diffusion mechanism is modified from 1-D to 3-D conduction, thereby improving kinetics. This is a refreshing perspective on antisite issues in the 1-D materials. Our model may provide hints to understand and enhance the electrochemical performance of other 1-D materials that suffer from kinetic limitations due to antisite defect through engineering of defect chemistry.

Assessment of dose and DNA damages in individuals exposed to low dose and low dose rate ionizing radiations during computed tomography imaging

PurposeComputed tomography (CT) is a frequently used imaging modality that contributes to a tenfold increase in radiation exposure to the public when compared to other medical imaging modalities. The use of radiation for therapeutic need is always rationalized on the basis of risk versus benefit thereby increasing concerns on the dose received by patients undergoing CT imaging. Therefore, it was of interest to us to investigate the effects of low dose and low dose-rate X-irradiation in patients who underwent CT imaging by recording the doses received by the eye, forehead and thyroid, and to study the levels of damages in the lymphocytes in vivo. Materials and methodsLithium manganese borate doped with terbium (LMB:Tb) thermo luminescence dosimeters (TLD) were used to record the doses in the patient’s (n=27) eye, forehead, and thyroid and compared with the dose length product (DLP) values. The in vivo DNA damages measured were compared before and after CT imaging using chromosomal aberration (CA) and micronucleus (MN) assays. ResultsThe overall measured organ dose ranged between 2±0.29 and 520±41.63mGy for the eye, 0.84±0.29 and 210±20.50mGy for the forehead, and 1.79±0.43 and 185±0.70mGy for the thyroid. The in vivo damages measured from the blood lymphocytes of the subjects showed an extremely significant (p<0.0001) increase in CA frequency and significant (p<0.001) increase in MN frequency after exposure, compared to before exposure. ConclusionThe results suggest that CT imaging delivers a considerable amount of radiation dose to the eye, forehead, and thyroid, and the observed increase in the CA and MN frequencies show low dose radiation effects calling for protective regulatory measures to increase patient’s safety. This study is the first attempt to indicate the trend of doses received by the patient’s eye, forehead and thyroid and measured directly in contrast to earlier values obtained by extrapolation from phantoms, and to assess the in vivo low dose effects in an Indian patient population undergoing CT procedures.

Microwave synthesis and electrochemical properties of lithium manganese borate as cathode for lithium ion batteries

Nano structured LiMnBO3/C cathode materials are synthesized by a fast microwave solid-state reaction method using MnCO3, Li2CO3, H3BO3 and glucose as starting materials for the first time. The crystal structure, morphology and electrochemical properties of LiMnBO3/C composites are characterized by X-ray diffraction (XRD), raman spectroscopy (Ramon), scanning electron microscopy (SEM), transmission electron microscopy (TEM), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and charge–discharge tests. The result shows that not only monoclinic LiMnBO3/C but also hexagonal LiMnBO3/C cathode materials can be successfully synthesized by microwave solid-state method with power of 240 W in different time. Compared with h-LiMnBO3/C and mixed phase LiMnBO3/C, m-LiMnBO3/C displays lower charge-transfer resistance and the Warburg impedance, so it reveals a higher first discharge capacity of 156.3 mAh g−1 at 0.05 C within 1.8V–4.6 V, The value increases up to 173.2 mAh g−1 caused by the activation process. Even after 50 cycles, the discharge capacity of m-LiMnBO3/C still remains at 148.2 mAh g−1.

One-dimensional manganese borate hydroxide nanorods and the corresponding manganese oxyborate nanorods as promising anodes for lithium ion batteries

Novel manganese and boron containing nanomaterials have been investigated for applications in rechargeable lithium ion batteries (LIBs) in recent years owing since they are more environmentally-benign and more abundant in nature than the materials currently employed. In this study, one-dimensional (1D) Mn3B7O13OH nanorods and MnBO2OH nanorod bundles were controllably fabricated by using NH4HB4O7 and Mn(NO3)2 as reagents via a hydrothermal or solvothermal process, respectively, without any surfactants or templates at 220 °C. It is interesting to find that both materials are transformed into Mn2OBO3 nanorods/nanorod bundles by subsequent calcination. The formation processes of the above 1D borate containing products were investigated and the as-obtained four kinds of borates were studied as novel anode materials. It was found that the Mn2OBO3 nanorods displayed the best performance among the four borates, delivering an initial discharge capacitiy of 1,172 mAh·g−1 at 100 mA·g−1, and 724 mAh·g−1 could be retained after 120 cycles. A full battery composed of a Mn2OBO3 nanorod anode and a commercial LiFePO4 (or LiCoO2) cathode has also been assembled for the first time, which delivered an initial discharge capacity of 949 mAh·g−1 (779 mAh·g−1 for LiCoO2). The excellent cycle and rate performances of the products reveal their potential applications as anodes for LIBs.

Enhanced Electrochemical Performance of Monoclinic LiMnBO3-Based Li Storage Material Via Partial Substitution

We developed a new electrochemically active Li storage material based on a polyanionic framework. By replacing a portion of Mn with Fe and Mg in monoclinic lithium manganese borate (LiMnBO3), a phase-pure LiMn0.5Fe0.4Mg0.1BO3 was successfully synthesized. A C/50-rate galvanostatic discharge delivered a near theoretical capacity of 201 mAh g-1 at room temperature with much improved rate capability, 120 mAh g-1 at a 1C discharge, compared to other borate chemistries. We explained this superior Li storage activity in relation to the topological effect of substitution, which leads to facile Li diffusion and stabilizes the structure. Combining with the inherent stability of the borate group against oxygen evolution, we believe that the enhanced electrochemical properties achieved in this study makes the LiMn0.5Fe0.4Mg0.1BO3 compound a strong contender as a new cathode material for Li-ion batteries and will bring more attention to the lithium transition metal borate chemistry.

Approaching the Theoretical Capacities of LiMnBO3

In the last decades, there have been a lot of studies on the LiFePO4 as a cathode material for lithium ion batteries. Its major target application was hybrid electric vehicles ( HEV ) and plug-in hybrid electric vehicle ( PHEV ). However, several hurdles remain before LiFePO4 can be deployed on a commercial scale because the material is still not capable enough to the energy density demand required for the electrical vehicles. The polyanion materials based on metal borate can be one of the solutions to replace ( PO4 3- ) anions due to high theoretical capacity, however, it has been reported that metal borate cathode materials could not make full use of its high theoretical capacities. We have successfully developed solid state synthesis method to produce lithium manganese borate ( LiMnBO3 ). Our experiments have shown that well synthesized LiMnBO3 delivers 190 mAh g-1 in the voltage range between 1.5 ~ 4.5 V using constant current-constant voltage ( CC-CV )mode at 1/20 C, which means that the theoretical capacity of LiMnBO3 can nearly be achieved under reasonable current density at room temperature by the simple synthesize method. This synthesis method allows the electrode of LiMnBO3 to deliver high capacity, even when charge/discharge experiments at the high C rate. More details will be discussed at the meeting.

Vibrational spectroscopy of the borate mineral chambersite MnB7O13Cl – Implications for the molecular structure

Chambersite is a manganese borate mineral with formula: MnB7O13Cl and occurs as colorless crystals in the monoclinic pyramidal crystal system. Raman bands at 902, 920, 942 and 963cm−1 are assigned to the BO stretching vibration of the B7O13 units. Raman bands at 1027, 1045, 1056, 1075 and 1091cm−1 are attributed to the BCl in-plane bending modes. The intense infrared band at 866cm−1 is assigned to the trigonal borate stretching modes. The Raman band at 660cm−1 together with bands at 597, 642 679, 705 and 721cm−1 are assigned to the trigonal and tetrahedral borate bending modes. The molecular structure of a natural chambersite has been assessed using vibrational spectroscopy.