Lithium Manganese Oxide Research Articles

The Role of Cations on the Performance of Lithium Ion Batteries: A Quantitative Analytical Approach.

Lithium ion batteries are nowadays the state-of-the-art power sources for portable electronic devices and the most promising candidate for energy storage in large-size batteries, e.g., pure and hybrid vehicles. However, the degradation of the cell components minimizes both storage and operation lifetime (calendar and cycle life), which is called aging. Due to the numerous different aging effects, in either the single constituents or their interactions with each other, many reports about methodologies and techniques, both electrochemical and analytical, can be found in the literature. However, quantitative data about the degradation effects were seldom stated. One important effect is the cation distribution and migration during operation. Metal dissolution and metal migration of the cathode and the corresponding deposition of these metals on the graphitic anode are known harmful degradation effects, especially for the formed solid electrolyte interphase on the surface of the anode. Depending on the applied cell chemistries and therefore the cathode material, different mechanisms were reported so far. For lithium manganese oxide based cells, the acidification of the electrolyte due to composition of the conduction salt is attributed as the main source of metal migration. Due to subsequent loss of manganese from the cathode, the overall performance of the cell is seriously impaired. Based on the obtained observations, this degradation mechanism was adapted to lithium nickel cobalt manganese based cells as main cause of the capacity fading. However, with the help a developed total X-ray fluorescence method and additional surface and electrolyte investigations, the proposed HF based mechanism was disproven. Instead, the migration was directly associated with material defects or mechanical spalling of the particles. Furthermore, with the obtained quantitative data of the migrated transition metals on the anode and separator, the contribution on the capacity fade was determined. It ranged only the ‰ region and could therefore be excluded as the main source of the capacity in these lithium ion batteries. Nevertheless, the oxidation state of the cations is hardly accessible; but would provide further information about the exact migrating mechanisms. In addition, lithium can be "lost" or immobilized during charge/discharge and is therefore no longer available as an electrochemically active cation. For example, the formation, reformation, and growth of the solid electrolyte interphase and cathode electrolyte interphase leads to an increased active lithium loss during cycling. The investigations on this topic are frequently reported in literature; however, quantitative data on the actual lithium distribution throughout the cell are relatively few. Furthermore, the exact amount of lost lithium in the in the respective interphases is so far not available. In order to determine quantitatively the lithium distribution within the cell, inductively coupled plasma-based method was applied. For laboratory test cells, the lithium that was lost to the housing of the cell was 32 times higher than that for pouch bag cells. Furthermore, the determined concentration of lithium in the interphases ranged only from 2 to 4%. However, the investigations need to be repeated with isotope labeled material (6Li) in order to obtain statements that are more precise.

Structural Characterization of the Li-Ion Battery Cathode Materials LiTixMn2–xO4 (0.2 ≤ x ≤ 1.5): A Combined Experimental 7Li NMR and First-Principles Study

Titanium doping in lithium manganese oxide spinels was shown to be beneficial for the structural stability of the potential Li-ion battery cathode materials LiTixMn2–xO4, 0.2 ≤ x ≤ 1.5, yet the distribution of Li/Ti/Mn in the structure and the cation oxidation states, both pivotal for the electrochemical performance of the material, are not fully understood. Our work investigates the changes in the local ordering of the ions throughout this series by using a combination of 7Li NMR spectroscopy and ab initio density functional theory calculations. The 7Li NMR shifts are first calculated for a variety of Li configurations with different numbers and arrangements of Mn ions in the first metal coordination shell and then decomposed into Li–O–Mn bond pathway contributions to the shift. These Li–O–Mn bond pathways are then used to simulate and assign the experimental NMR spectra of different configurations and stoichiometries beyond those in the initial subset of configurations via a random distribution model an...

Approaching the lithium-manganese oxides' energy storage limit with Li2MnO3 nanorods for high-performance supercapacitor

Lithium manganese oxides are of great interest due to their high theoretical specific capacity for electrochemical energy storage. However, it is still a big challenge to approach its large theoretical limit. In this work, we report that Li2MnO3 nanorods with layered structure as superior performance electrode for supercapacitors. The synthesized Li2MnO3 nanorods possess large specific surface area of 179.5m2/g. The electrode made of the as-obtained Li2MnO3 nanorods exhibits high specific capacitance of 1129.5F/g at 2mV/s in 3M LiCl electrolyte. Detailed electrochemical analysis shows that diffusion controlled processes contribute most of the relative capacity. First-principles calculations within density functional theory also show that the diffusion of Li+ ions in the lithium layer is much easier than that in the manganese-lithium-oxygen layer. Therefore, the ion flow in lithium layer provides most of the high specific capacitance during charge/discharge. A flexible symmetric supercapacitor is assembled based on Li2MnO3/carbon fabric cloth. Such device demonstrates high specific capacitance, high energy density, high power density and excellent cycling stability. Three supercapacitors in series can efficiently power 288 blue LEDs in parallel for about 11min. These results indicate that Li2MnO3 nanorods are very promising as super electrode material for supercapacitors.

Considering Battery Degradation in Life Cycle Greenhouse Gas Emission Analysis of Electric Vehicles

Lithium ion batteries (LIBs) are predominantly employed to power Electric Vehicles (EVs). Battery degradation can significantly affect battery performance and further influence the energy consumptions and life cycle greenhouse gas (GHG) emissions from EVs. However, currently battery degradation has not been taken into account in life cycle assessment (LCA) of EVs. In this paper, we report our research on considering battery degradation into life cycle GHG emissions of EVs, by analyzing a mid-size EV using a 24 kWh Lithium-Manganese-Oxide (LMO)-graphite battery. Both cycling loss and calendar loss in battery degradation are analyzed under average driving conditions of U.S. The model is validated with experimental testing data on Nissan Leaf from Argonne National Lab. In this study, the required battery replacement is also integrated into the LCA GHG emission model and results, by considering the cradle-to-gate GHG emissions from a battery pack. This model can improve the accuracy and reliability of life cycle GHG studies on EVs.

Characteristics of organic-inorganic composite sorbent prepared using lithium hydroxide and manganese oxide for recovery of lithium ions

Characteristics of organic-inorganic composite sorbent prepared using lithium hydroxide and manganese oxide for recovery of lithium ions

Multi-Species, Multi-Reaction Model for Porous Intercalation Electrodes: Part I. Model Formulation and a Perturbation Solution for Low-Scan-Rate, Linear-Sweep Voltammetry of a Spinel Lithium Manganese Oxide Electrode

We formulate and implement a porous electrode model that includes multiple lithium-insertion species and associated electrochemical and homogenous reactions. This multi-species, multi-reaction (MSMR) model can account for the multiple current peaks observed in voltammetry data at slow scan rates and is also consistent with X-ray diffraction analysis of several different electrode materials. The MSMR model is used to simulate linear-sweep voltammetry data of a porous electrode of spinel lithium manganese oxide at different scan rates, and an analytic solution to these equations at very slow scan rates is given, based on a perturbation analysis. The greatest sensitivity at these slow scan rates is to the thermodynamic parameters, because the electrode is close to a state of dynamic equilibrium. The poor sensitivity to transport parameters means that it is not possible to distinguish between transport effects and a small amount of hysteresis that could be present in the slow-scan voltage measurements. These facts are illustrated using both the analytic solution and its comparison to numerical calculations. In Part 2, the analytic solution will be combined with numerical simulations at higher scan rates to complete the fitting process of transport, kinetic and thermodynamic parameters, along with a small amount of hysteresis.

Investigation of the exceptional charge performance of the 0.93Li4−xMn2O5–0.07Li2O composite cathode for Li-ion batteries

Herein, we report a detailed study on the high-energy density nanostructured Li4−xMn2O5–Li2O composite with a high discharge capacity of 355 mA h g−1, constituting the highest value reported to date for a lithium–manganese oxide electrode.

A metal-ion-chelating organogel electrolyte for Le Chatelier depression of Mn3+disproportionation of lithium manganese oxide spinel

Mn dissolution resulting from Mn3+disproportionation in lithium manganese oxide spinel was significantly depressed by a metal-ion-chelating organogel electrolyte.

Insight into fast Li diffusion in Li-excess spinel lithium manganese oxide

Li-excess configuration can enhance Li diffusion by introducing two fast channels in spinel lithium manganese oxide.

Direct Detection of Manganese Ions in Organic Electrolyte by UV-vis Spectroscopy

Lithium manganese oxide cathodes used in Li-ion batteries suffer from manganese dissolution and capacity fade. We present a new technique for directly measuring the manganese ion (Mn2+) concentration in a typical Li-ion carbonate electrolyte using 4-(2-pyridylazo) resorcinol (PAR) as a UV-vis probe. Chelation between PAR and Mn2+ ion induces a characteristic absorption peak where the peak intensity corresponds to Mn2+ ion concentration in the electrolyte. Electrochemical stability of the probe is verified by performing potential hold and cyclic voltammetry. The in situ characterization of Mn dissolution in a customized battery cell is performed during cyclic voltammetry.

Highly porous and surface-expanded spinel hydrogen manganese oxide (HMO)/Al2O3 composite for effective lithium (Li) recovery from seawater

Lithium (Li) recovery from seawater is currently attracting great attention due to increasing industrial demand. Hydrogen manganese oxide (HMO) is a promising adsorbent for Li recovery from seawater, but powder-type HMO is difficult to apply and it is essential to obtain a granulated material for practical application. To minimize Li adsorption capacity loss and to obtain high mechanical stability in seawater, highly porous cylindrical HMO/Al2O3 composites have been synthesized, and their Li adsorption behavior has been investigated in seawater. Various ratios (1:4, 1:5, 1:9, 1:19, and 1:39) of lithium manganese oxide (LMO):alumina gel were tested for the synthesis of HMO/Al2O3 composites. All of the LMO/Al2O3 composites exhibited large surface area owing to the mesoporous character of γ-Al2O3. By increasing the Al2O3content in the composite, the surface area is expanded and a more porous structure is obtained, but the crystallinity of the spinel phase of LMO is decreased.After delithiation, the HMO/Al2O3 composite was applied for Li adsorption from seawater. HMO/Al2O3 composites exhibited similar Li uptakes compared to HMO powder (ca. 9 mg Li/g HMO) due to their highly expanded surface area and porous structure. During the recovery of Li adsorbed on the HMO/Al2O3 composites by acid treatment, more manganese (Mn) was dissolved from composites containing more Al2O3 due to the low crystallinity of the spinel HMO. Finally, it was found that HMO/Al2O3 containing 25% Al2O3 exhibited less than 1% Mn dissolution, and its Li adsorption performance did not decrease over five Li adsorption–desorption cycles.

Grain boundary transport in sputter-deposited nanometric thin films of lithium manganese oxide

The lithium intercalation into ion-beam sputter-deposited films of lithium manganese oxide is studied as a function of the film thickness (50–500nm). The kinetics of the intercalation is quantified in cyclic voltammetry under variation of the scanning rate over five orders of magnitude (0.005–768mV/s). With an increasing rate, the intercalation currents reveal a transition from a finite length diffusion to a semi-infinite diffusion behavior, as it is expected from continuum transport equations. But surprisingly, the peak current in the Randles-Sevcik regime scales with the square root of film thickness. Consequently, the diffusion coefficient apparently increases with the layer thickness. Combining the parameters of the actual microstructure of the thin films with an appropriate kinetic modeling that includes the effects of grain boundaries, it is shown that the observed acceleration is quantitatively understood by outstandingly fast short-circuit transport in a type B kinetic regime of grain boundary diffusion.

Environmental impact analysis and process optimization of batteries based on life cycle assessment

As an energy storage device, battery has been rapid developed in recent years with the typical environmental problems such as consumption of resources and heavy metal pollution. Therefore, it is urgent to conduct a comprehensive analysis and in-depth interpretation of the environmental impact of the battery industry to reduce environmental pollution. Life cycle assessment is applied to analyze and compare the environmental impact of lead acid battery (LAB), lithium manganese battery (LMB) and lithium iron phosphate battery (LIPB) within the system boundary of “cradle-to-gate”. The key processes and the key substances of environmental impact are identified by the traceability. The results showed that the overall impact of LIPB production on environment is the smallest. The key substances that cause the environmental impact of LAB production process are refined lead and tin. Lithium manganate and aluminum shell are the key substances that cause the environmental impact of lithium manganese oxide production process. The key substances that cause the environmental impact of lithium iron phosphate production process are lithium iron phosphate and aluminum shell. According to the position of each key substance in the process, the Reduce-Reuse-Recycle principle of circular economy theory is adopted to suggest the corresponding optimization. This research can provide useful reference for government decision-making and the sustainable development of battery industry.

Stabilized Lithium, Manganese AB2O4 Spinel for Rechargeable Lithium Electrochemical Systems through A and B Site Doping

Lithium manganese oxide doped with potassium and cobalt produces a promising cathode material for rechargeable lithium-ion cells. Modifying the A site and B site of the spinel structure works to limit cathodic capacity fading by enhancing the robustness of the material. LixKyMn2-zCozO4 was synthesized as the active ingredient for the cathode with x=1, y=0.1, and both z=0.1 and 0.2, and was tested against metallic lithium to evaluate performance. Through high-rate discharge, pulse cycling, and deep discharge tests, the electrochemistry of the cathode exhibited excellent reversibility and overall performance stability. LiK0.1Mn2-zCozO4 proved to be a capable abuse tolerant option for use in rechargeable battery applications.

Cycle Life Performance of LixMn2-yFeyO4-zClz Made via in Situ Combustion Synthesis

Lithium manganese oxide spinel is an attractive material for lithium-ion battery cathodes due to its 3D network of lithium pathways within the structure. An inherent disadvantage is its limited cyclability as a result of the energy barriers for removing lithium from the octahedral sites. This work incorporates chlorine into the lattice of the high surface area material to help assist in lithium deinsertion and can be synthesized for use in less than 8 hours by using the common ceramic synthesis technique of glycine nitrate combustion. The electrochemical cell cycled between 4.75V and 3.5V at 1mA/cm2 (9mA/gactive) and achieves over 130 cycles in this work while maintaining a capacity of 82.3mAh/g, about 95% of the its greatest capacity.

Electrochemical Performance of LixMn2-yFeyO4-zClz Synthesized through in Situ Glycine Nitrate Combustion

Lithium manganese oxide spinel is an attractive material for lithium-ion battery cathodes due to its 3D network of lithium pathways within the structure. However this material suffers from limited cyclability as a result of the energy barriers for removing lithium from the octahedral sites and capacity fading as a result of manganese dissociation. This work incorporates chlorine into the lattice of the high surface area material to help assist in lithium deinsertion and can be synthesized for use in less than 8 hours by using the common ceramic synthesis technique of glycine nitrate combustion. The resulting electrochemical cells cycle between 4.5 V and 3.5 V at 1.0 mA cm-2 (10 mA gactive-1) and achieve over 250 cycles while maintaining a capacity of 71 mAh/g, about 98% of the its original capacity. Additionally when cycled to 2.25 V the electrochemical cell is completely reversible and delivered a capacity of 150 mAh/g.

Selective lithium recovery from aqueous solution using a modified membrane capacitive deionization system

Selective lithium recovery from aqueous solutions containing various cations (Li+, Na+, K+, Ca2+, and Mg2+) was tested using a modified membrane capacitive deionization system consisting of a lithium manganese oxide electrode for lithium ion capturing and a carbon electrode for anion capturing. The effect of cations and their concentrations on lithium ion selectivity was investigated. The results showed that the selectivity order found in the collected solutions was Li+≫Mg2+>Ca2+>K+>Na+. This order indicates that the ionic radius and oxidation state affect the selectivity. Approximately 0.35μmol/g-adsorbent of lithium was recovered, which is 7 times higher than that from the physisorption process under the same experimental conditions. The required energy in the recovery process was calculated as 23.3Wh/g of lithium. The results were reproducible, and no manganese dissolution was observed during 5 consecutive recovery cycles.

3D Printing of a Complete Lithium Ion Battery

The ability to make a lithium ion battery (LIB) in an arbitrary shape could enable customization of the form factor of a battery to better fit the shape of a given product. To this end, numerous fabrication methods have been developed to construct LIBs into thin 2D films, various 2D shapes, wires, and interdigitated microbatteries.1 - 4 However, to be fully customizable, ideally all the components of the battery, including the anode, cathode, separator, current collector, and case, would be 3D printable. To make this approach widely accessible, it would be beneficial if each part of the battery could be printed with low-cost, fused filament fabrication (FFF) 3D printers. Batteries made in this way could potentially also serve as the structural components of a product. This presentation will describe how to make complete LIBs with an FFF 3D printer. A key hurdle to creating 3D printable batteries is the ionic conductivity of the polymers typically used for FFF 3D printing are too low. After testing many solvents, we found the ionic conductivity of polylactic acid (PLA), the most common polymer used for 3D printing, could be increased by more than 10 orders of magnitude (from 8.2 x 10−14 S cm−1 to 2.3 x 10−4 S cm−1) by infusing the polymer with a mixture of ethyl methyl carbonate, propylene carbonate, and LiClO4. The ionic conductivity of the infused PLA is comparable to the mixture of LiClO4 and solvents (9 x 10−3 S cm−1). After selecting PLA as the polymer for the filament, it was found that up to 12 volume % of solids could be mixed into the polymer without causing it to clog during 3D printing. Lithium titanate (LTO) and lithium manganese oxide (LMO) were selected for the active materials in the anode and cathode, respectively, and a 90:10 ratio of conductive carbon to active material maximized their charge storage capacity. Testing of carbon black SuperP, nanocarbon, and carbon nanotubes as conductive fillers indicated that the high conductivity enabled by long carbon nanotubes led to the highest charge storage capacity. The relatively low amount of active material in the anode and cathode led to low capacities (< 1 mAh/g) for the fully printed battery. However, this capacity was sufficient to demonstrate the lighting of LEDs with 3D printed batteries integrated into an eyeglasses frame (Figure 1A&B) and a bangle bracelet (Figure1 C&D). Future improvements in the battery might be attainable by finding a way to 3D print a battery composite with a higher loading of active materials and yet retain comparable mechanical properties. In addition, the high ionic conductivity of infused PLA suggests the use of this polymer as an electrolyte may be worth additional study.

New Operando Technique to Detect Manganese Dissolution from Lithium Manganese Oxide Electrodes

Lithium manganese oxide is a promising cathode material for the next generation of lithium ion batteries due to its high capacity, low cost, and low toxicity. However, LMO electrode suffer from rapid capacity loss due to degradation of the active material by manganese dissolution into the electrolyte. Significant scientific effort has recently been devoted to understanding the effect of environmental and operating parameters on Mn2+ dissolution (e.g. storage temperature, electrolyte acidity and overcharge/ overdischarge conditions). Yet, no experimental data exits for Mn2+ dissolution during lithiation and delithiation, due to lack of experimental techniques to monitor the Mn2+ ion concentration in real-time in the electrolyte while the battery is in operation. Here we report an in-operando experimental technique to detect the concentration of Mn2+ ions in electrolyte using a UV-vis probe molecule (4-(2-pyridylazo) resorcinol, PAR) and activator (1,8-bis(dimethylamino)naphthalene, proton sponge) combination. Chelation between the probe molecule and Mn2+ ion induces a color change in the electrolyte, enabling in-operando characterization of Mn2+ dissolution via spectroscopy. The probe molecule is highly selective, and can selectively differentiate trace amount of Mn2+ ions compared to concentrated Li+ ions in the electrolyte solution. The electrolyte consisted of 1 mol/L LiPF6 in ethylene carbonate/ dimethyl carbonate (1:1 by volume). Mn2+ ions were introduced into the electrolyte by dissolving different amounts of manganese(II) acetylacetonate (Mn(acac)2). Figure 1a shows the range of color of the electrolyte with respect to the concentration of manganese ions. The electrolyte was analyzed by UV-vis spectroscopy and the absorption peak is shown to shift from 490 nm to 534 nm (Figure 1b). When the Mn2+ ion concentration is stoichiometrically lower than probe concentration, all Mn2+ ions in the solution are assumed to be chelated with the probe molecules. Thus, the absorption peak intensity of chelated molecules at the characteristic wavelength (534 nm) is proportional to concentration (Figure 1c), which follows the Beer-Lamber law. Mn2+ concentration in the electrolyte can thus be determined spectroscopically without interfering with the natural operation of Li-ion batteries. Figure 1

Cycle Life Analysis of LiMn2O4-DCld Made Via in Situ Combustion Synthesis and Reduced-Time Solid State Processing

Lithium manganese oxide spinels exhibit promising electrochemical performance and good thermodynamic and kinetic stability when used as a cathode in lithium and lithium-ion electrochemical systems. This can be attributed to its inherent three-dimensional structure that allows lithium ions to easily flow in and out of the lattice. A common disadvantage of this chemistry is its limited cyclability as a result of the energy barriers for removing lithium from the octahedral sites. Additionally, the dissolution of manganese ions into the electrolyte causes both capacity fading and cycle life degradation in an electrochemical system. CERDEC has previously demonstrated enhanced electrochemical performance at both low and high voltage ranges, with the reversible region occurring between 2.0 V to 4.75 V. This material incorporates chlorine into the lithium manganese spinel structure using a reduced-time solid state processing method, where the material is calcined in air at 600 °C for 2 hours. This method drastically reduces the processing time and calcining temperature in comparison to the traditional hydrothermal fabrication method or the standard solid state method for lithiated manganese spinels. The general formula for the halogenated lithium manganese spinel material is LixMn2O4-dXd, where x ≈ 1 and d ranges from 0.005 to 0.3. This work focuses on further evaluating the cycle life performance of electrochemical cells utilizing this LiMn2O4-dCldcathode material in the high voltage operating range. Additionally, an alternative processing method is analyzed for halogenated lithium manganese spinel, where the material is made via in situ combustion synthesis in order to further promote lithium deinsertion from octahedral sites. Incorporating chlorine into the lithium manganese spinel structure further stabilizes the lattice to prevent manganese dissolution into the electrolyte when utilized in an electrochemical cell. The alternative processing method involves using a glycine nitrate combustion process, where the ash is collected and calcined in air at 600 °C for 2 hours. Material analysis was performed using X-ray diffraction, X-ray fluorescence, thermogravimetric analysis, BET surface area analysis, and scanning electron microscopy to evaluate and verify the composition and structure of the chlorinated spinel material, as well as its particle morphology. This alternative processing method allows for a more uniform structure in the desired spinel phase with higher surface area. Electrochemical coin cells were fabricated utilizing LiMn2O4-dCld against a lithium anode, where the cathode material was synthesized using both processing methods. Test cells were cycled between 3.5 V and 4.75 V at 0.5-1 mA/cm2 to determine cycle life capability and capacity degradation processes. A comparative performance evaluation was also performed by incorporating undoped cathode material into electrochemical coin cells and conducting galvanostatic testing under the same test regime. A cycle life graph is shown displaying the capacity retention of electrochemical coin cells incorporating an undoped lithium manganese spinel, LiMn2O4-dCld synthesized using a glycine nitrate combustion process (GNP), and LiMn2O4-dCld synthesized using the reduced time solid state process (RTP). These cells were cycled between 3.5 V and 4.75 V at 0.5 mA/cm2. The data shows increased capacity retention, above 95% at 130 cycles, using the alternative processing method, GNP. Additionally, a clear degradation and recovery of capacity of the undoped lithium manganese spinel cell is shown, which is attributed to the cell being cycled at a voltage range that is higher than optimal. Figure 1