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[Nithya Hellar](https://orcid.org/0000-0002-0359-0355), Yoshiki Iwai, Masato Ohzu, Sebastian Brox, [Arunkumar Dorai](https://orcid.org/0000-0001-5296-263X), Reiji Takekawa, [Naoaki Kuwata](https://orcid.org/0000-0002-0736-6967), Junichi Kawamura, Martin Winter

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[Direct observation of Mn-ion dissolution from LiMn2O4 lithium battery cathode to electrolyte](https://mdr.nims.go.jp/datasets/f2a42d08-cfcb-4a43-9cae-6640ae4da546)

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Direct observation of Mn-ion dissolution from LiMn2O4 lithium battery cathode to electrolytecommunicationsmaterials Articlehttps://doi.org/10.1038/s43246-025-00733-2Direct observation of Mn-ion dissolutionfrom LiMn2O4 lithium battery cathode toelectrolyteCheck for updatesNithya Hellar 1,2 , Yoshiki Iwai1,3, Masato Ohzu1, Sebastian Brox4, Arunkumar Dorai 1,Reiji Takekawa1, Naoaki Kuwata 1,5, Junichi Kawamura1 & Martin Winter4,6The degradation of lithium-ion batteries has become a concerning issue. One problem is metal iondissolution from the cathode material, such as Mn2+ dissolution from spinel-type LiMn2O4 (LMO).However, direct observation of the dissolution process has yet to be reported. Here, we establish in-situ 1H nuclear magnetic resonance imaging (MRI) measurement as an efficient technique to observeMn2+ dissolution from amodel lithium battery with LMO as the cathode.We observe an increase in theMRI signal intensity near the cathode, confirming the dissolution of Mn2+ from the cathode to theelectrolyte. Moreover, we show that Mn2+ dissolution from LMO can be suppressed using anappropriate choice of electrolytes. We believe the method developed here can answer the long-timeunanswered question of when, where, and how the metal ion dissolution occurs in the lithium-ionbattery electrode and can be extended to other electrochemical systems.Spinel-type LMO and its derivatives are promising cathode materialsfor the development of batteries suitable for electric vehicles due totheir high operating voltage, low cost, and safe performance1.Although LMO operates at high voltage, it has its own disadvantageof structural instability and capacity fading when operated atpotentials >4.3 V. The reason for capacity fading is (i) electrolytedecomposition when operated at high potential, (ii) phase change(Jahn-Teller distortion/structural instability), and (iii) dissolution ofmanganese (Mn) to the electrolyte through hunter’s dis-proportionation reaction [2Mn3+(s) →Mn4+(s)+Mn2+(l)]2–4. Amongthese, active metal dissolution (Mn) is the most serious problem forlong-time applications such as electric vehicles and smart gridapplications, where slow deterioration of battery performance causesmaintenance problems and increases the lifetime cost.For over a decade, several reports were published on differentmethodsto suppress Mn dissolution and develop a highly stable LMO. Also, fewreports are found that quantitatively measure dissoluted Mn ion con-centration in the electrolyte5–10. Tounderstand themetal iondissolution, it isimportant to detect when, where, and howmuch the dissolution happens inthe lithium batteries. Therefore, developing a new analytical techniquesensitive to the metal ions in electrode materials of battery systems is war-ranted.Moreover, developing in-situ techniqueswill help in future efforts toimprove battery design and performance.Nuclear magnetic resonance imaging (MRI) is a non-invasivetechnique, which combines spectroscopy and imaging, makes it apowerful tool and is widely used in various applications such asbatteries, fuel cells, corrosion cells, and metallurgy11–20. However, noreports have focused on identifying the metal ion dissolution inlithium batteries using in-situ MRI [see Supplementary Table 1 forpast reports on application of MRI in battery research]. Also, ourgroup first reported that proton (1H) MRI is a suitable technique tovisualize the degradation of battery electrolytes in a model lithiumbattery21. In the present work, we demonstrate the direct observationand quantification of Mn ion dissolution from LMO cathode usingin-situ 1H MRI. Further, we identified an electrolyte system thatsuppresses the metal ion dissolution from LMO.1Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, 980-8577, Japan. 2New IndustryCreation Hatchery Center (NICHe), Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, 980-8577, Japan. 3Technology and Innovation Division, PanasonicCorporation, 3-1-1 Yagumo-naka-machi, Moriguchi City, Osaka, 570-8501, Japan. 4MEET Battery Research Center, Institute of Physical Chemistry, University ofMünster, Corrensstraße 46, 48149 Münster, Germany. 5Research Center for Energy and Environmental Materials, National Institute of Materials Science (NIMS),1-1 Namiki, Tsukuba, Ibaraki, 305-0044, Japan. 6Helmholtz Institute Münster (IEK-12), Forschungszentrum Jülich GmbH, Corrensstraße 46, 48149Münster, Germany. e-mail: hellar.nithya.e4@tohoku.ac.jp; junichi.kawamura.a8@tohoku.ac.jpCommunications Materials |            (2025) 6:23 11234567890():,;1234567890():,;http://crossmark.crossref.org/dialog/?doi=10.1038/s43246-025-00733-2&domain=pdfhttp://crossmark.crossref.org/dialog/?doi=10.1038/s43246-025-00733-2&domain=pdfhttp://crossmark.crossref.org/dialog/?doi=10.1038/s43246-025-00733-2&domain=pdfhttp://orcid.org/0000-0002-0359-0355http://orcid.org/0000-0002-0359-0355http://orcid.org/0000-0002-0359-0355http://orcid.org/0000-0002-0359-0355http://orcid.org/0000-0002-0359-0355http://orcid.org/0000-0001-5296-263Xhttp://orcid.org/0000-0001-5296-263Xhttp://orcid.org/0000-0001-5296-263Xhttp://orcid.org/0000-0001-5296-263Xhttp://orcid.org/0000-0001-5296-263Xhttp://orcid.org/0000-0002-0736-6967http://orcid.org/0000-0002-0736-6967http://orcid.org/0000-0002-0736-6967http://orcid.org/0000-0002-0736-6967http://orcid.org/0000-0002-0736-6967mailto:hellar.nithya.e4@tohoku.ac.jpmailto:junichi.kawamura.a8@tohoku.ac.jpwww.nature.com/commsmatResults and discussionTheory and scope of MRI in lithium battery electrolyteIn principle, the MRI signal intensity, when obtained using the spin-echotechnique, is given byIðx; yÞ / ρðx;yÞ 1� exp�TRT1� �� �exp�TET2� �ð1Þwhere TR and TE are repetition and echo time, which are experimentalparameters. T1 and T2 are spin-lattice relaxation, and spin-spin relaxationtime, which are material properties. Therefore, from Eq. 1, MRI signalintensity is clearly affected when T1 and T2 relaxation time changes. Byvarying the experimental parameters, we can obtain contrast-enhancedimages that are either T1 weighted (longitudinal relaxation), T2 weighted(transverse relaxation), or proton density weighted images. A comparativeimage intensity plot generated by varying the parameters used in Eq. 1 isshown in Fig. 1a. However, there is no exact reference range. In this study,we have used the change in the relaxation time of the solvent protons in theelectrolyte ethylene carbonate (EC), and dimethyl carbonate (DMC) in thepresenceofdissolutedMn2+, a paramagnetic nuclei to indirectly observe andquantify the Mn amount dissoluted into the electrolyte.Calibration of 1H MRI signal intensity with manganese (Mn2+)concentrationThe changes in 1H MRI signal intensity in the presence of paramagneticMn2+were validatedusing gel electrolyte (1M lithiumhexafluorophosphate(LiPF6) in EC:DMC+ poly(vinylidene fluoride-co-hexafluoropropylene)(PVdF-HFP)) with different concentrations of MnCl2 (0, 24, 48 μM). Theresults are shown in Fig. 1b, c, where the image contrast increases linearlywith an increase inMn2+ concentration. This is due to the decrease in the T1relaxation time of the protons in EC/DMC with increasing Mn con-centration [relaxation time of the electrolyte is given in SupplementaryTable 2]. A calibration was determined by linear least square fit, giving thefollowing equationY ¼ 3:6 ð± 0:23Þ x 106 Xþ 53:547 ð± 7Þ ð2ÞThe result indicated that we could detect manganese ions in theorder of μM.Earlier reports have shown thatMRI images are strongly affectedby thepresence of localmagnetism from the electrodematerials andmetals used inbatteries16,22. Therefore, we have investigated the effect of current collectorsand cathode material on the MR images. The schematic diagram of thehomemade cell used for the in-situ 1H MRI measurement is shown inSupplementary Fig. S1a, b. The parameters and conditions were optimizedso that the images were not affected/distorted by the magnetic property ofthe materials used, as shown in Supplementary Fig. S2a–c. Moreover, theeffect of the current under the magnetic field during in-situ measurementwas studied briefly, and the results are shown in SupplementaryFigs. S3 and 4).Dissolution of Mn2+ in conventional electrolyteThe in-situ 1H MRI measurement results for Li/LMO cell using 1M LiPF6EC:DMC electrolyte is shown in Fig. 2(a–c). The charge–discharge profile isshown in Fig. 2a, and MR images acquired at regular intervals duringcharging and discharging is shown in Fig. 2b. The image acquired beforeFig. 1 | Evolution of MRI signal intensity. aMRIintensity change calculated according to Eq. 1, withrespect to change in relaxation time, bMR images ofstandard MnCl2 in 1M LiPF6 EC:DMC gel electro-lyte (i) 0 (ii) 24 and (iii) 48 μM Mn2+, c Mn2+ con-centration dependence of average MRI signalintensity extracted from (b).https://doi.org/10.1038/s43246-025-00733-2 ArticleCommunications Materials |            (2025) 6:23 2www.nature.com/commsmatapplying current (Fig. 2b(A)) shows an even distribution of the signalintensity.During chargingbetween4.1–4.7 V, signal intensitynear theLMOcathode increases significantly, and beyond 4.7 V, a strong increase in theintensity is observed (Fig. 2b(G)). The gradual increase in signal intensityduring charging indicates the presence of manganese in the electrolyte,which affects the T1 relaxation of the solvent protons in the electrolyte (EC/DMC), leading to the increase in signal intensity (Supplementary Table 2).During discharge, the intensity near the LMO cathode spreads throughthe cell.For qualitative analysis, the averageMRI signal intensity was extractedand is shown inFig. 2c. The intensity gradually increased from~4.1 Vwherea plateau begins to appear (Fig. 2a). This increase in signal intensity isattributed to the presence of dissoluted manganese in the electrolyte fromthe LMO cathode. Although the experiments were performed in controlledatmosphere, trace amount ofH2O in the electrolyte is unavoidable, resultingin the formation of HF. During the charging process at ~4.1 V, lithium isgradually deintercalated from the LMO cathode, and a lithium-deficientphase is formed on the surface locally, which reacts with HF to form λ-Mn2O4 phase according to the following reaction23 processLi1�xMn2O4 þHF ! λ�Mn2O4 þ LiFþMn2þ þH2O ð3Þwhere the Mn2+ ions get dissoluted into the electrolyte. This result corro-borates with Dong et al., who reported a similar process to occurabove 4.1 V7.Beyond 4.7 V, a rapid rise in the MRI signal intensity is observed. Ascharging proceeds, oxygen is released from the LiyMn2O4 cathode (Eq. 3),leading to the oxidation of the electrolyte24.LiyMn2O4 þ 2δe� ! LiyMn2O4�δ þ δO2� ð4ÞWhenoxygen is released fromLiyMn2O4 cathode, the concentration ofunstableMn3+ ions increase, leading to faster and larger disproportionationof manganese ions from the LMO electrode (2Mn3+ →Mn4+ +Mn2+)25–27.Further, the MRI signal intensity increases continually and extends up to4.1 V during discharge. This is because themanganese ions dissoluted fromthe surface of LMOcathode tend to accumulate in the electrolyte.Moreover,due to hydrodynamic flow of the electrolyte, the intensity spreadsthroughout the entire cell. After discharging the cell to lower voltages, noconsiderable change in the signal intensity was observed (SupplementaryMovie 1).In addition, a circular flow pattern appears near the Li anodethroughout the charge–discharge cycle (Fig. 2b), which is due to the elec-trochemical convection in the cell19,28. We skip the discussion about con-vection phenomena here because the present article focuses on thevisualization and quantification of Mn ion dissoluted from LMO cathode.The electrochemical convection affects the observed intensity profile of themanganese distribution significantly, restricting our quantitative analysis ofmanganese dissolution. To avoid this problem, we used a gel electrolyteconsisting of 1M LiPF6 EC: DMC with PVdF-HFP polymer.Quantification of Mn2+ concentrationThe charge–discharge profile andMR images for the gel electrolyte system isshown in Fig. 3a, b, which shows similar behavior to that of the liquidelectrolyte system. The MR images of the gel electrolyte indicate that theelectrochemical convection effect observed near the lithiummetal anode inthe liquid electrolyte system is suppressed, which enables us to analyze themanganese dissolution into the electrolyte quantitatively. The MR imagesobtained at much shorter intervals are shown in Supplementary Fig. S6 andSupplementary Movie 2.The average MRI signal intensity change with respect to charging anddischarging is shown in Fig. 3c. The average intensity increases during thecharging process (Fig. 3c blue circles). Like the liquid electrolyte system,above 4.1 V gradual increase in the signal intensity is observed due to thepresenceof dissolutedmanganese8.Contrary to the liquid electrolyte system,during the discharging process, the MRI signal intensity does not decrease.Also, we extracted the image intensity near the cathode and is shown inFig. 3c (red circles), where the MRI signal intensity increases till theFig. 2 |Observation of dissolutedmanganese. aCharge–discharge profile for LiMn2O4/1MLiPF6 EC:DMC/Li cell,b 1HMR images acquired at potentialsmentioned in (a),and (c) 1H MRI signal intensity corresponding to the active cell area (the square region between the electrodes marked in the blue frame in (b).https://doi.org/10.1038/s43246-025-00733-2 ArticleCommunications Materials |            (2025) 6:23 3www.nature.com/commsmatcompletion of the charging process and remains the same during dischar-ging. In the absence of the electroconvection effect, the dissoluted manga-nese remains within the cell throughout the discharge process (Fig. 3b, c).Furthermore, manganese may be dissoluted into the electrolyte duringdischarge where the disproportionation reaction occurs faster. However, wecannot distinguish the contribution of manganese dissoluted during thedischarge process at present.Wehave converted theMR images intoMn2+ concentrationmapusingthe calibration curve (Fig. 1c) and shown in Fig. 3d. These maps showdistribution of dissoluted Mn2+ ions from cathode into the electrolyte, andits propagation towards the anode. The maximum Mn2+ concentrationestimated from the concentrationmap is 36 μM.To estimate the totalMn2+dissoluted, we acquired MR images in the horizontal plane (XY) near thecathode, center of the cell and near the anode (Supplementary Fig. S6c, d).The amount ofMn2+ near the cathode, center of cell and near the anodewas28.6, 22.1, and 6.26 μM, respectively. Further, the actual volume of theregion used to estimate the manganese concentration (region enclosed inblue in Supplementary Fig. S6c) near the cathode, center of the cell and nearthe anode was calculated to be 2.94 × 10−5 L, 2.94 × 10−5 L and 13.5 × 10−5 Lrespectively. Considering the actual volume estimated, the amount ofmanganese estimatednear the cathode, center of the cell, andnear the anodewas found to be 8.42 ×10−10 mol, 6.51 × 10−10 mol, and 8.45 × 10-10 mol,respectively. Therefore, the total estimated amount of manganese in the cellusing MRI was found to be 2.34 × 10−9 mol. Further, the amount of man-ganese dissoluted into the electrolyte was estimated to be 20.6 × 10−9 molusing ICP-AES measurements. The observed difference in the concentra-tion estimated from MRI and ICP techniques is because the manganeseconcentration was estimated after 3 cycles using ICP, whereas the con-centration from MRI is from one cycle only. Besides, the concentrationestimated from both techniques falls in the same order. This demonstratesthat usingMRI techniquemetal iondissolution in the order of fewμMcouldbe detected efficiently.Suppression of Mn2+ dissolutionFor comparison, the same experiment was carried out on a single solventether-based electrolyte methyl-3-cyanopropanoate (MCP) with lithiumbis(trifluoromethane)-sulfonylimide (LiTFSI) as conductive salt29. Thechoiceof new solvent and salt basedon cyanoesters andLiTFSI, respectively,is to inherent high electrochemical stability and suppress HF formation29,30.This was expected to suppress the Mn2+ dissolution during the electro-chemical charge–discharge process. The charge–discharge profile forLiMn2O4/1M LiTFSI MCP/Li cell system is shown in Fig. 4a. Thecharge–discharge profile appears similar to that of 1M LiPF6 EC: DMC(Fig. 3a). The acquired 1HMR images and the average MRI signal intensityfor LiMn2O4/1M LiTFSI MCP/Li cell system are shown inFig. 4(b, c). In the case of 1M LiPF6 EC: DMC, image intensity graduallyincreased near the surface of LiMn2O4, indicating the dissolution of Mn2+ion into the electrolyte during charging. However, in the case of 1MLiTFSIMCP during charging, no considerable increase in image intensity wasobserved, indicating that Mn dissolution was suppressed in 1M LiTFSIMCP electrolyte system (Fig. 4b, c). During discharge when the current isreversed, a slight increase in image intensity was observed, which might bedue tomanganese dissoluted into the electrolyte during discharge followingthe disproportionation of Mn3+ to Mn4+ and Mn2+ and the intensity beingspreadout of the cell due tohydrodynamicflowof the electrolyte.The imageintensity change is small when compared to the gel electrolyte results,indicating that manganese dissolution is suppressed in the LiTFSI MCPsystem (Supplementary Movie 3).Fig. 3 |Mapping ofmanganese concentration. aCharge–discharge profile for LMOcell with gel electrolyte. bMR images acquired at potential marked in red in (a) and(c) MRI signal intensity change with respect to time extracted from the active cellregion (region enclosed in the blue frame in ((b)(A)) and near the LMO cathode(region enclosed in the red frame in ((b) (B)). dMn2+ concentrationmapped imagesacquired at potentials indicated.https://doi.org/10.1038/s43246-025-00733-2 ArticleCommunications Materials |            (2025) 6:23 4www.nature.com/commsmatConclusionsWe have illustrated a simple spin-echo technique with appreciable acqui-sition time to identify dissoluted Mn2+ in the electrolyte by 1H MRI. Ourresults prove in-situMRI to be a promising tool in visualizing when, where,and how Mn2+ dissolution occurs from LiMn2O4 electrode into the elec-trolyte. This approach helps in exploring the metal ion dissolution in anyelectrochemical systems under different electrochemical conditions, such aschanging the electrolyte solution, salt, electrodes, and additives. This iden-tification method helps to design lithium battery materials and improvetheir performance. In the present case, we identified an electrolyte (1MLiTFSIMCP) that suppressesMn2+ dissolution due to electrolyte oxidationduring the charging process. Furthermore, MRI technique providesadvantages over other techniques because it can estimate even extremelysmall concentration (μM) of dissoluted metal ions.MethodsElectrodeThe positive electrode was prepared by mixing LiMn2O4 (Aldrich) as anactive material, PVdF (Wako Pure Chemical Industries, Ltd.) as a binder,and acetylene carbon black (WakoPureChemical Industries, Ltd.) at amassratio of 85:9:6 using N-Methyl-2-Pyrrolidone NMP (Kishida Kagaku) as asolvent. The prepared slurry was coated on the aluminum foil with athickness of 50 μm. Care was taken to obtain uniform active material ofthickness 75 μm. The active electrode material was dried at 80 oC andpressed at 40MPa for 5min, and the total thickness of the electrodewas 59 μm.Liquid electrolyteIn the present study, two types of electrolytes were investigated (1) 1MLiPF6 EC:DMC (1:1 v/v) (Kishida chemical co.) and (2) 1M LiTFSI MCP.The MCP sample was received from MEET Battery Research Center,Münster, Germany.Gel electrolyteThe gel electrolyte was prepared by dissolving PVdF-HFP (KYNAR FLEX2801-00) in 1M LiPF6 EC:DMC (1:1) with a stoichiometry of 30mg/Lat 353 K.In-situ MRI cellThe specially designed homemade experimental cell used for in-situ MRImeasurements is shown in Supplementary Fig. S1. The cells for the in-situMRImeasurements were assembled in a controlled argon atmosphere withthe dewpoint of−88 °C. The LMOcathode and the Limetal anode (0.1 mmthickness and 10mm diameter) were separated by a hollow cylindricalspacer made of PEEK with an inner diameter and thickness of 5mm. Forsafety concerns of the battery operation, a groove was introduced in thespacer, which acts as a vent for gas/bubbles to escape. For electrical contact,Pt and teflon-coatedCuwirewereusedon theLMOpositive andLi-negativeelectrodes, respectively.Electrochemical measurementThe galvanostatic charging and discharging was carried out using TohoGiken PS–08 potentiostat/galvanostat instrument at a constant current of±25 µA in both the liquid and gel electrolyte systems.Nuclear magnetic resonance imaging (MRI)The 1H NMR imaging measurement was carried out using BrukerAvance–400 NMR spectrometer operating at 9.4 T. A triple-axis gradientprobe with vertical sample loading is used for the 1H NMR imaging. Thetwo-dimensional 1H MR images were acquired using spin-echo pulsesequence. In-situ MR images were acquired with a slice thickness of1.48mm, size 30 × 30mm and, a spatial resolution of 234 µm. The acqui-sition parameters suchas echo time and repetition timewerefixed as 9.0 and500ms for the 1MLiPF6 EC:DMCsystem. For the gel electrolyte systemTEand TR were fixed as 9.0 and 1000ms respectively. For 1M LiTFSI MCPelectrolyte system TE and TR were fixed as 10.4 and 500ms, respectively.The number of integration times (NS) was four. The minimum acquisitiontime to obtain a single image was 4min 16 s. The open-source ImageJsoftware was used for further analysis of the images. All the measurementswere performed at 20 °C.Inductivelycoupledplasmaatomicemissionspectroscopic (ICP-AES) measurementsTo quantitatively determine the dissoluted manganese concentration,a cell similar to that for in-situ MRI measurement was constructedand galvanostatiscally charged and discharged under similar condi-tions. After completing three cycles, the electrolyte was collected andthe dissoluted manganese concentration was examined using PerkinElmer’s Optima 3300XL inductively coupled plasma (ICP) emissionspectrometer.Received: 19 September 2024; Accepted: 6 January 2025;Fig. 4 | Suppression of manganese dissolution.aCharge–discharge profile for LiMn2O4/1MLiTFSIMCP/Li cell, b 1H MR images acquired at potentialsmentioned in (a), and (c) 1H MRI signal intensitychange during charging and discharging.https://doi.org/10.1038/s43246-025-00733-2 ArticleCommunications Materials |            (2025) 6:23 5www.nature.com/commsmatReferences1. Thackeray, M. M. & Amine, K. LiMn2O4 spinel and substitutedcathodes. Nat. Energy 6, 566 (2021).2. Wen, S. J. et al. FTIR spectroscopy of metal oxide insertion electrodes: anew diagnostic tool for analysis of capacity fading in secondary Li/LiMn2O4 cells. J. Electrochem. Soc. 143, L143–L146 (1996).3. Arora, P.,White, R. 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ChemElectroChem 4,304–309 (2017).AcknowledgementsThis work was supported by the Research and Development Innovative forScientific Innovation of New Generation Battery (RISING) project from NewEnergy and Industrial Technology Development Organization (NEDO),Japan. One of the authors, S. B. is grateful to the Japan Society for thePromotion of Science (JSPS) for the Post-Doctoral Research Fellowship(Grant Number: [PE-17701]).Author contributionsN.H. and Y.I. contributed equally to this work. J.K. conceived the projectidea. N.H., Y.I., M.O., and S.B. performed the experiments, analyzed andinterpretedwithA.D.,R.T.,N.K., andJ.K. J.K. andM.W.supervised thework.All authors contributed to the writing of the manuscript. All authors havegiven approval to the final version of the manuscript.Competing interestsThe authors declare no competing interests.Additional informationSupplementary information The online version containssupplementary material available athttps://doi.org/10.1038/s43246-025-00733-2.Correspondence and requests for materials should be addressed toNithya Hellar or Junichi Kawamura.Peer review information Communications materials thanks Yu Qiao,Bingwen Hu, and the other, anonymous, reviewer(s) for their contribution tothe peer review of this work. Primary handling editors: Guangmin Zhou andJet-Sing Lee. A peer review file is available.Reprints and permissions information is available athttp://www.nature.com/reprintsPublisher’s note Springer Nature remains neutral with regard tojurisdictional claims in published maps and institutional affiliations.https://doi.org/10.1038/s43246-025-00733-2 ArticleCommunications Materials |            (2025) 6:23 6https://doi.org/10.1038/s43246-025-00733-2http://www.nature.com/reprintswww.nature.com/commsmatOpen Access This article is licensed under a Creative CommonsAttribution-NonCommercial-NoDerivatives 4.0 International License,which permits any non-commercial use, sharing, distribution andreproduction in any medium or format, as long as you give appropriatecredit to the original author(s) and the source, provide a link to the CreativeCommons licence, and indicate if you modified the licensed material. Youdo not have permission under this licence to share adapted materialderived from this article or parts of it. The images or other third partymaterial in this article are included in the article’s Creative Commonslicence, unless indicated otherwise in a credit line to thematerial. If materialis not included in thearticle’sCreativeCommons licenceandyour intendeduse is not permitted by statutory regulation or exceeds the permitted use,you will need to obtain permission directly from the copyright holder. Toview a copy of this licence, visit http://creativecommons.org/licenses/by-nc-nd/4.0/.© The Author(s) 2025https://doi.org/10.1038/s43246-025-00733-2 ArticleCommunications Materials |            (2025) 6:23 7http://creativecommons.org/licenses/by-nc-nd/4.0/http://creativecommons.org/licenses/by-nc-nd/4.0/www.nature.com/commsmat Direct observation of Mn-ion dissolution from LiMn2O4 lithium battery cathode to electrolyte Results and discussion Theory and scope of MRI in lithium battery electrolyte Calibration of 1H MRI signal intensity with manganese (Mn2+) concentration Dissolution of Mn2+ in conventional electrolyte Quantification of Mn2+ concentration Suppression of Mn2+ dissolution Conclusions Methods Electrode Liquid electrolyte Gel electrolyte In-situ MRI cell Electrochemical measurement Nuclear magnetic resonance imaging (MRI) Inductively coupled plasma atomic emission spectroscopic (ICP-AES) measurements References Acknowledgements Author contributions Competing interests Additional information