Lithium Manganese Oxide Cathode Research Articles

Unveiling electrochemical insights of lithium manganese oxide cathodes from manganese ore for enhanced lithium-ion battery performance

Implementing manganese-based electrode materials in lithium-ion batteries (LIBs) faces several challenges due to the low grade of manganese ore, which necessitates multiple purification and transformation steps before acquiring battery-grade electrode materials, increasing costs. At present, most Lithium Manganese Oxide (LMO) materials are synthesized using electrolytic manganese dioxide, and the development of new processes, such as hydrometallurgical processes is important for achieving a cost-effective synthesis of LMO materials. In this work, we develop a full synthesis process of LMO materials from manganese ore, through acid leaching, forming manganese sulfate monohydrate (MnSO4·H2O), an optimized thermal decomposition (at 900, 950 or 1000 °C) producing different Mn3O4 materials and a solid-state reaction, achieving the synthesis of LMO. The latter was used as a cathode material for LIB exhibiting a specific capacity comparable to the state-of-the-art LMO cathode with a remarkable cycling stability of 800 cycles with <20 % in capacity loss. These performances were attributed to the excellent redox reversibility of the LMO cathode, characterized by voltammetry and in operando and in situ characterization by Raman and XRD.

Green and Sustainable Recovery of MnO2 from Alkaline Batteries for High-Performance Lithium Manganese Oxide Cathode

Green and Sustainable Recovery of MnO₂ from Alkaline Batteries for High-Performance Lithium Manganese Oxide Cathode

Enhancing performance and sustainability of lithium manganese oxide cathodes with a poly(ionic liquid) binder and ionic liquid electrolyte

Current battery production involves various energy intensive processes and the use of volatile, flammable and/or toxic chemicals. This study explores the potential for using a water-soluble and functional binder, poly(diallyldimethylammonium) (PDADMA) with diethyl phosphate (DEP) as a counter anion, for lithium manganese oxide (LMO) cathodes. By replacing the traditional polyvinylidene fluoride (PVDF) binder and its associated toxic N-methyl-2-pyrrolidone (NMP) solvent, PDADMA-DEP offers a more sustainable and cost-effective solution. Notably, PDADMA-DEP electrodes do not require high-temperature calendaring to achieve high performance unlike PVDF electrodes. X-ray Photoelectron Spectroscopy (XPS) indicated significant interactions between the binder and LMO that enhance stability and ion conduction. The PDADMA-DEP binder demonstrated excellent electrochemical rate capability up to 10C with the conventional organic liquid electrolyte (LP30), outperforming PVDF electrodes. The performance of both binders using a safer and non-volatile ionic liquid electrolyte, specifically 50 mol% LiFSI in N-trimethyl-N-propylammonium bis(fluorosulfonyl)imide, was also investigated to enhance the overall safety and environmental impact of the battery system. IL-based cells utilizing a PDADMA-DEP cathode binder demonstrated a 58 % capacity retention over 500 cycles at 0.5C when cycled at room temperature.

The enhancement and impact of Se doping on the electrochemical properties of LiMn2O4 cathode material for aqueous Li-ion batteries

Spinel LiMn2O4 is a promising cathode material for lithium-ion batteries. However, due to the Jahn-Teller effect and Mn dissolution, its capacity decreases seriously in the cycle process, which hinders its wider application. In the course of our research, we discovered that a modest infusion of Se-doping is capable of significantly augmenting the oxygen vacancy within the material, improve the conductivity of the LiMn2O4 material and promotes superior battery performance. Moreover, due to Se-doped the average valence state of Mn is raised, which effectively mitigates the Jahn-Teller effect. The optimized sample exhibits high capacity, long cycle life, and superior rate capability, with an initial discharge specific capacity of 101.0 mAh·g−1 at 7 C and capacity retention of 87.3 % after 200 cycles. The maximum specific discharge capacity of the full battery during the cycle was 97.9 mAh·g−1, the capacity retention rate after 200 cycles was 78.2 %, and the maximum energy density during the cycle is 145.1 Wh·Kg−1, which was nearly twice that of the single lithium-ion battery in this paper. The effect of Se-doped on the properties of LiMn2O4 cathode materials provides a new idea for the development of high-performance spinel lithium manganese oxide cathode materials.

Developing a High‐Performing Spinel LiMn2O4 Cathode Material with Unique Morphology, Fast Cycling and Scaled Manufacture

AbstractHigh power application of Li‐battery remains a challenge due to the lack of stable fast‐charging cathode materials. Lithium manganese oxide (LMO) cathode is very promising due to its high operating voltage and fast charging ability; however, the associated Mn‐dissolution is one of the main hindrances to its practical applicability. In this work, we demonstrate for the first time the use of a commercially scalable method through a proprietary Calix flash calcination (CFC) technology to develop high‐performance electrode materials where a novel CXL LMO material was manufactured and tested. CXL LMO|Li metal cell showed a reversible specific capacity of 110 mAh/g with 99 % retention after 100 cycles and showed excellent rate performance up to 20 C current rate (~20 mA/cm2 current density). CXL LMO|Graphite cell (areal capacity 1 mAh/cm2) was also reported with 86 % capacity retention over more than 500 cycles. Cross‐section morphology revealed a unique multi‐layered structure that was retained at the core of the novel LMO material. It obtained lesser Mn dissolution compared to commercial LMO. The scalable synthesis procedure through CFC technology, can be broadly applicable to produce unique electrode morphology as demonstrated here for the CXL LMO representing a promising pathway for electrode manufacturing for high‐power Li‐batteries.

Identifying Current Collectors that Enable Light-Battery Interactions.

In recent years, there has been an increased focus on studying light-battery interactions in the context of operando optical studies and integrated photoelectrochemical energy harvesting. However, there has been little insight into identifying suitable "light-accepting" current collectors for this class of batteries. In this study, fluorine-doped tin oxide, indium-tin oxide, and silver nanowire-graphene films are analyzed along with carbon paper, carbon nanotube paper, and stainless-steel mesh as current collectors for optical batteries. They are categorized into two classes - transmissive and non-transmissive, based on the orientation of the light-electrode interaction. Various methods to prepare the electrode are highlighted, including drop casting and the fabrication of free-standing electrodes. The optical and electrical properties of these current collectors as well as their electrochemical stability are measured using linear sweep voltammetry against zinc and lithium anodes. Finally, the rate performance and long-term cycling stability of lithium manganese oxide (LiMn2O4) cathodes are measured against lithium anodes with these current collectors and their performance is compared. These results show which current collector to choose depends on the application and cell chemistry. These guidelines will assist in the design of future optical cells for in-situ measurements and photoelectrochemical energy storage.

Boosting LiMn2O4 Diffusion Coefficients and Stability via Fe/Mg Doping and MWCNT Synergistically Modulating Microstructure

The dissolution of manganese and its deposition on the anode surface cause poor cycling stability in lithium-ion batteries. To alleviate these issues, this study probes the electrochemical activity of highly crystalline and cation-adjusted lithium manganese oxide (LMO) carbon spinel composite obtained via a modified sol-gel synthesis procedure. The pristine LMO cathode was functionalized with a Fe and Mg alloy and fused with purified multiwalled carbon nanotubes (MWCNTs) to form a catalytically stabilized LiMn1.98Fe0.01Mg0.01O4/MWCNT (LMO-FeMg/MWCNT) framework. High-resolution SEM analysis showed well-dispersed particles in the nanometer size range. The electrochemical characteristics of the novel composite materials yielded favourable electrochemical results with diffusion coefficients of 1.91 × 10−9 cm2·s−1 and 5.83 × 10−10 cm2·s−1 for LMO-FeMg and LMO-FeMg/MWCNT, respectively. This improvement was supported by impedance studies which showed a considerable Rct reduction of 0.27 Ω and 0.71 Ω. The cation stabilized system outperformed the pristine LMO material with specific capacities around 145 mAh·g−1, due to an enhancement in electrochemical activity and structural stability.

Lessons Using an Electrochemical Method to Produce Lithium Manganese Oxide Cathodes for Lithium-Ion Batteries

Lithium manganese oxide (LMO) has been a well-studied Li-ion battery cathode material for for many years. It offers high thermal stability for high-temperature battery applications and a prolonged cycle life compared to other materials. LMO also has an acceptably high energy density from a naturally abundant, inexpensive, and environmentally benign material, i.e. manganese (Mn). The cathodes for LIBs are conventionally synthesized via solid-state reaction techniques, which require harsh and complex conditions including high temperature (> 700oC) and high pressure. The resulting powders are incorporated into a slurry that is cast onto a current collector using a binder, additives, and solvent. Though this results in high-performing electrodes, it also usually increases the production cost. Another approach that is gaining traction to make LMOs is electrodeposition. Electrodeposition can allow for the direct synthesis of the active material on the current collector without using any binder or additives. Using electrodeposition not only could eliminate the mass and volume of inactive material but also reduce the cost of electrode fabrication. It also can facilitate recycling by depositing the active material from lower purity, material-digested streams.A few reports in the literature have discussed the electrochemical preparation of LMO cathode from the following steps: electrodeposition of manganese oxide (s) (MnxOy) onto a substrate followed by chemical lithiation and heat treatment of MnxOy [1,2]. Although a few reports showed the active materials with reasonable capacity, it is presently unknown what LiMnxOy phase or phases are active and which MnxOy is responsible. However, without sufficient physicochemical investigation, multiple works have postulated that the LMO is created from crystalline MnO2 or Mn3O4. It is also not known what the typical active phase yield is or what physical structures or conditions are responsible for increased capacity. If electrodeposition-to-LMO is to become a viable commercial pathway, a rational understanding of the solid-state chemistry for the LMO formation is needed.This talk will discuss the deposition and lithiation of multiple manganese oxide phases – linking the chemistry and morphology of the surface features to their charge/discharge properties. It will be shown that traditional crystalline phases are not responsible for the formation of LMOs. It will also be shown that the LMOs do not fully delithiate during charging. Lastly, the precise morphology of the active phase – separated out through new processing approaches – will be identified. The composition, structure, and crystallinity of the Mn oxides and LMOs were characterized by X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The resulting LMO electrodes were incorporated into coin cells, cycled – achieving a capacity of 261 mAh g-1, and post-characterized.References J. Rana, M. Stan, R. Kloepsch, J. Li, G. Schumacher, E. Welter, I. Zizak, J. Banhart, and M. Winter, Adv. Energy Mater., 4, 1300998 (2014).Z. Quan, S. Ohguchi, M. Kawase, H. Tanimura, and N. Sonoyama, J. Power Sources, 244, 375 (2013).

Enhanced LiMn2O4 Thin-Film Electrode Stability in Ionic Liquid Electrolyte: A Pathway to Suppress Mn Dissolution.

Spinel-type lithium manganese oxide (LiMn2O4) cathodes suffer from severe manganese dissolution in the electrolyte, compromising the cyclic stability of LMO-based Li-ion batteries (LIBs). In addition to causing structural and morphological deterioration to the cathode, dissolved Mn ions can migrate through the electrolyte to deposit on the anode, accelerating capacity fade. Here, we examine single-crystal epitaxial LiMn2O4 (111) thin-films using synchrotron in situ X-ray diffraction and reflectivity to study the structural and interfacial evolution during cycling. Cyclic voltammetry is performed in a wide range (2.5-4.3 V vs Li/Li+) to promote Mn3+ formation, which enhances dissolution, for two different electrolyte systems: an imidazolium ionic liquid containing lithium bis-(trifluoromethylsulfonyl)imide (LiTFSI) and a conventional carbonate liquid electrolyte containing lithium hexafluorophosphate (LiPF6). We find exceptional stability in this voltage range for the ionic liquid electrolyte compared to the conventional electrolyte, which is attributed to the absence of Mn dissolution in the ionic liquid. X-ray reflectivity shows a negligible loss of cathode material for the films cycled in the ionic liquid electrolyte, further confirmed by inductively coupled plasma mass spectrometry and transmission electron microscopy. Conversely, a substantial loss of Mn is found when the film is cycled in the conventional electrolyte. These findings show the significant advantages of ionic liquids in suppressing Mn dissolution in LiMn2O4 LIB cathodes.

Evaluation of cracking damage in electrode materials of a LMO/Al-Lix lithium-ion battery through analysis of acoustic emission signals

Damage due to the internal degradation of electrode materials in lithium-ion batteries (LIBs) during charge-discharge cycles can cause capacity fading and safety issues. Therefore, it is essential to assess damage to LIBs using nondestructive methods. In this study, the relationship between the damage mechanism and acoustic emission (AE) activity of a commercial lithium manganese oxide (LMO)/Al-Lix alloy battery is systematically investigated. Microstructural observations of the electrodes revealed that the damage mechanisms of the LMO cathode and Al-Lix anode during accelerated charge-discharge were identical to those of microcracking. Energy, amplitude, duration, rise time, and peak frequency were considered as possible AE parameters for real-time damage detection. The generation of AE hits was prominent during the later stages of the charging and discharging processes. The AE signals produced by damage to the Al-Lix alloy anode during charging had a lower amplitude (0–60 dB) and energy (0–10 aJ). In comparison, those produced by damage to the LMO cathode during charging had a relatively high amplitude (100 dB) and energy (120 aJ). Additionally, the energy levels and amplitudes of the AE signals obtained during discharging decreased with an increasing number of cycles, indicating that they can be used as indicators for evaluating the damage progression of the primary, secondary, and tertiary cracks in LMOs. The AE technique offers the possibility of monitoring and evaluating the damage to the anode and cathode of a commercial full cell separately, as well as predicting the remaining capacity of the battery by monitoring the AE hits.

A thin Si nanowire network anode for high volumetric capacity and long-life lithium-ion batteries

Silicon nanowires (Si NWs) have been widely researched as the best alternative to graphite anodes for the next-generation of high-performance lithium-ion batteries (LIBs) owing to their high capacity and low discharge potential. However, growing binder-free Si NW anodes with adequate mass loading and stable capacity is severely limited by the low surface area of planar current collectors (CCs), and is particularly challenging to achieve on standard pure-Cu substrates due to the ubiquitous formation of Li+ inactive silicide phases. Here, the growth of densely-interwoven In-seeded Si NWs is facilitated by a thin-film of copper-silicide (CS) network in situ grown on a Cu-foil, allowing for a thin active NW layer (<10 µm thick) and high areal loading (≈1.04 mg/cm2) binder-free electrode architecture. The electrode exhibits an average Coulombic efficiency (CE) of >99.6% and stable performance for >900 cycles with ≈88.7% capacity retention. More significantly, it delivers a volumetric capacity of ≈1086.1 mA h/cm3 at 5C. The full-cell versus lithium manganese oxide (LMO) cathode delivers a capacity of ≈1177.1 mA h/g at 1C with a stable rate capability. This electrode architecture represents significant advances toward the development of binder-free Si NW electrodes for LIB application.

A social life cycle assessment of vanadium redox flow and lithium‐ion batteries for energy storage

AbstractBattery energy storage systems (BESS) are expected to fulfill a crucial role in the renewable energy systems of the future. Within current regulatory frameworks, assessing the sustainability as well as the social risks for BESS should be considered. In this research we conducted a social life cycle assessment (S‐LCA) of two BESS: the vanadium redox flow battery (VRFB) and the lithium‐ion battery (LIB). The S‐LCA was conducted based on the guidelines set by UNEP/SETAC and using the PSILCA v.3 database. It was found that most social risks related to the life cycle of the batteries are associated with the raw material extraction stage, while sectors related to chemicals also entail considerable risks. Workers are the stakeholder group affected most. These results apply to supply chains located in both China and Germany, but risks were lower for similar supply chains in Germany. An LIB with a nickel manganese cobalt oxide cathode is associated with considerably larger risks compared to a LIB with lithium manganese oxide cathode. For a VRFB life cycle with an increased vanadium price, the social risks were higher than those of the VRFB supply chain with a regular vanadium price. Our paper shows that S‐LCA through the PSILCA database can provide interesting insights into the potential social risks associated with a certain product's life cycle. Generalizations of the results are not recommended, and one should be careful with assessments for technologies that have not yet matured due to the cost sensitivity of the methodology.

Effects of a Sodium Phosphate Electrolyte Additive on Elevated Temperature Performance of Spinel Lithium Manganese Oxide Cathodes.

LiMn2O4 (LMO) spinel cathode materials suffer from severe degradation at elevated temperatures because of Mn dissolution. In this research, monobasic sodium phosphate (NaH2PO4, P2) is examined as an electrolyte additive to mitigate Mn dissolution; thus, the thermal stability of the LMO cathode material is improved. The P2 additive considerably improves the cyclability and storage performances of LMO/graphite and LMO/LMO symmetric cells at 60 °C. We explain that P2 suppresses the hydrofluoric acid content in the electrolyte and forms a protective cathode electrolyte interphase layer, which mitigates the Mn dissolution behavior of the LMO cathode material. Considering its beneficial role, the P2 additive is a useful additive for spinel LMO cathodes that suffer from severe Mn dissolution.

Recycling diesel soot nanoparticles for use as activated carbon in Li ion batteries

We report the successful capture and reuse of diesel exhaust soot particles as a conductive additive in lithium manganese oxide (LMO) and lithium iron phosphate (LFP) cathodes in Li-ion batteries. This approach enables an abundant toxic pollutant to be converted into a valuable material for energy storage devices. This study consists of an initial characterization of the diesel soot particles, a high-temperature annealing step to remove residual organics and unburned hydrocarbons, and characterization of the electrical performance in a Li-ion battery configuration. Here, composite electrodes are fabricated by mixing active materials (LFP or LMO) with conductive carbon and binders. The performance of the diesel soot particles as conductive additives is compared with that of commercially available activated carbon (i.e., Super P®). The current evolution of the composite electrode made with diesel soot particles demonstrates comparable performance to the electrodes containing the Super P® carbon. Based on high-resolution transmission electron microscope (HRTEM) images and scanning mobility particle sizer (SMPS) spectra, we find that these diesel soot nanoparticles follow a narrow log-normal distribution centered around 100 nm in diameter and consist of highly porous amorphous carbon, which provide a large surface-to-volume ratio, making them ideal candidates for electrode materials in Li ion batteries.

Efficient Direct Recycling of Degraded LiMn2O4 Cathodes by One-Step Hydrothermal Relithiation.

Due to the large demand of lithium-ion batteries (LIBs) for energy storage in daily life and the limited lifetime of commercial LIB cells, exploring green and sustainable recycling methods becomes an urgent need to mitigate the environmental and economic issues associated with waste LIBs. In this work, we demonstrate an efficient direct recycling method to regenerate degraded lithium manganese oxide (LMO) cathodes to restore their high capacity, long cycling stability, and high rate performance, on par with pristine LMO materials. This one-step regeneration, achieved by a hydrothermal reaction in dilution Li-containing solution, enables the reconstruction of desired stoichiometry and microphase purity, which is further validated by testing spent LIBs with different states of health. Life-cycle analysis suggested the great environmental and economic benefits enabled by this direct regeneration method compared with today's pyro- and hydrometallurgical processes. This work not only represents a fundamental understanding of the relithiation mechanism of spent cathodes but also provides a potential solution for sustainable and closed-loop recycling and remanufacturing of energy materials.

Enhanced Electrochemistry of Carbon Supported Functionalized Nanocomposite Cathode for Aqueous Lithium‐ion Batteries

AbstractA novel carbon supported LiMn2O4 nanocomposite framework has been explored to resolve multiple barriers associated with lithium manganese oxide cathodes for aqueous LIB systems. Here, we have successfully synthesized an architecturally stable AlF3−LiMn2O4/rGO composite with improved electron transfer kinetics and CV peak currents proportional to the square root of scan rate. The synergy between graphene and aluminium trifluoride enhances the intrinsic electrochemical properties of pristine LiMn2O4 (LMO) and reduced Mn+3 dissolution. The unique composite effectively reduced Li+ diffusion distances with less polarization as it effectively accommodates the structural transformation during Li+ ion charge and discharge. The electrochemical interrogation revealed faster charge transportation and decrease in charge transfer resistance due to inhibition of the pronounced pile‐up of Li+ ions and undesired Mn3+ ions on the surfaces. The electrochemical performances were tested in LiNO3 aqueous electrolyte and the cell delivered a capacity of 90 mA h g−1 based on the total weight of the active electrode materials. This aqueous LIB cathode system provides a promising alternative for safe, cost‐effective and scalable energy storage with tolerance against misuse.

Degradation-guided optimization of charging protocol for cycle life enhancement of Li-ion batteries with Lithium Manganese Oxide-based cathodes

Conventional charging protocols are typically indifferent to battery degradation, hence leading to suboptimal cycle life performance of the battery. An optimized charging protocol with priority towards battery health is thus an untapped opportunity to enhance useful life. We propose a physics-optimized dynamic charging protocol, extending the cycle life of the system by up to 50% without compromising the battery capacity, by considering a lithium ion battery system with Lithium Manganese Oxide cathode as an example. The algorithm takes into account the nuances of the system considering the available capacity, degradation mechanisms and operational voltage windows to dynamically moderate the charging protocol during run time, leading to optimized life span of the battery. The protocol is very versatile and can be easily extended to any battery chemistry prone to degradation at high/low cut off voltages, which allows enhancement of the battery life simply by changing the on-board charging algorithm.

Characterization of Li+ and Na+ Insertion into Sodium Titanium Phosphate

Due to their high energy density, lithium-ion batteries based on organic electrolytes are ubiquitous in applications such as consumer electronics. However, high capital costs and flammability of the electrolyte have limited their use in residential or grid storage. An alternative involves replacing the organic solvent-based electrolytes with aqueous electrolytes and using electrochemical couples that operate within the water electrolysis stability window. Aqueous electrolytes have several advantages, such as ease of manufacturing, greater safety, and more cell design flexibility due to the higher conductivity compared to organic electrolytes 1.In addition to aqueous Li-ion batteries, aqueous Na-ion batteries have attracted significant interest due to the increased availability of Na on earth and further cost reductions1,2. Furthermore, aqueous commercial batteries using electrolytes containing both Li+ and Na+ exist. For example, one such battery using a lithium manganese oxide cathode, a sodium titanium phosphate (NTP) anode, and a Li2SO4/Na2SO4 electrolyte has been commercialized by companies such as Aquion Energy and BenAn Energy2. Despite the advantages described previously, the operating voltage window of aqueous electrolytes is smaller than that of its organic counterparts. In addition, insertion behavior in aqueous electrolytes is more complex than what is observed in organic electrolyte systems3. This can be further complicated when using electrolytes with more than one cation4,5. One such example involves the insertion of Li+ and Na+ into NTP. In electrolytes where Na+ is the only cation, a single redox couple attributed to Na+ insertion is observed on CV experiments. Meanwhile, when both Li+ and Na+ are present, insertion of both cations occurs, with equilibration occurring after 10 CV cycles4. Despite this interesting behavior, little is known as to how the Li2SO4/Na2SO4 ratio affects the insertion behavior of NTP.In this work, the effect of Li2SO4 and Na2SO4 concentration in the insertion behavior will be characterized using CV and galvanostatic cycling with ion monitoring. CV experiments will be used to characterize the relative extent of insertion for both Li+ and Na+ and the insertion potentials. Meanwhile, galvanostatic cycling will be used to assess the connection between the CV results and charge/discharge plateaus observed under different Li2SO4/Na2SO4 ratios. In addition, ion monitoring will be performed every 50 cycles at relevant conditions (bottom and top of charge and intermediate points) to measure concentration changes in the electrolyte concentrations. Furthermore, galvanostatic intermittent titration cycles will be incorporated into the cycling regime to characterize the effect of concentration in the open circuit voltage (OCV) and resistance, as well as exploring changes in these variables as a function of cycling.

A High-Rate Lithium Manganese Oxide-Hydrogen Battery.

Rechargeable hydrogen gas batteries show promises for the integration of renewable yet intermittent solar and wind electricity into the grid energy storage. Here, we describe a rechargeable, high-rate, and long-life hydrogen gas battery that exploits a nanostructured lithium manganese oxide cathode and a hydrogen gas anode in an aqueous electrolyte. The proposed lithium manganese oxide-hydrogen battery shows a discharge potential of ∼1.3 V, a remarkable rate of 50 C with Coulombic efficiency of ∼99.8%, and a robust cycle life. A systematic electrochemical study demonstrates the significance of the electrocatalytic hydrogen gas anode and reveals the charge storage mechanism of the lithium manganese oxide-hydrogen battery. This work provides opportunities for the development of new rechargeable hydrogen batteries for the future grid-scale energy storage.

Garnet–PVDF composite film modified lithium manganese oxide cathode and sulfurized carbon anode from polyacrylonitrile for lithium-ion batteries

Composite film of polyvinylidene difluoride (PVDF) and Li5.6Ga0.26La2.9Zr1.87Nb0.05O12 garnet improves the cycling stability and rate capability of lithium manganese oxide (LMO) cathode.