{
  "node": {
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    "type": "Term",
    "label": "Operando and in-situ measurement",
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      "section": "topic-analysis",
      "definition": "Measuring a cell inside its working environment rather than after taking it apart (ex situ): in situ means within the cell or its surroundings, operando means while it is actually charging or discharging. Operando methods catch transient states, such as phases or plated lithium that vanish during rest or disassembly.",
      "related": [
        "post-mortem",
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        "differential-electrochemical-mass-spectrometry",
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      "id": "topic:topic-analysis",
      "type": "Topic",
      "label": "Materials analysis and post-mortem",
      "properties": {
        "id": "topic-analysis",
        "name": "Materials analysis and post-mortem",
        "lede": "The laboratory techniques that look inside electrodes, interphases and electrolytes to see what a cell is made of and how it aged.",
        "context": "Connect results with scale and specimen preparation.",
        "example": "Surface and bulk measurements may find different compositions in the same electrode without contradiction.",
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        "lesson_label": "Open materials lab"
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      "id": "term:post-mortem",
      "type": "Term",
      "label": "Post-mortem analysis",
      "properties": {
        "id": "post-mortem",
        "name": "Post-mortem analysis",
        "aka": [
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        ],
        "section": "topic-analysis",
        "definition": "Opening an aged or failed cell in an inert glovebox and examining its electrodes by microscopy, diffraction and chemical analysis. It confirms which degradation mechanisms actually occurred rather than inferring them from voltage.",
        "related": [
          "aging-mechanism",
          "scanning-electron-microscopy",
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      "id": "term:x-ray-diffraction",
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        "name": "X-ray diffraction",
        "abbr": "XRD",
        "section": "topic-analysis",
        "definition": "Identifying crystal structures from the angles at which they scatter X-rays. It tracks lithium content and phase changes in electrode materials, and operando XRD follows them while the cell cycles.",
        "related": [
          "phase-transition",
          "structural-degradation",
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      "id": "term:differential-electrochemical-mass-spectrometry",
      "type": "Term",
      "label": "Differential electrochemical mass spectrometry",
      "properties": {
        "id": "differential-electrochemical-mass-spectrometry",
        "name": "Differential electrochemical mass spectrometry",
        "abbr": "DEMS",
        "aka": [
          "OEMS",
          "online electrochemical mass spectrometry"
        ],
        "section": "topic-analysis",
        "definition": "Feeding gas from an operating cell straight into a mass spectrometer, so each species is identified and quantified as it forms. It shows ethylene from ethylene carbonate reduction during formation, and the oxygen and carbon dioxide released by layered oxides at high state of charge, tying each gas to the voltage that made it.",
        "related": [
          "gas-generation",
          "off-gas",
          "electrolyte-decomposition",
          "formation",
          "operando-measurement",
          "gas-chromatography-mass-spectrometry"
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        "url": "https://lemonergy.com/learn/glossary/differential-electrochemical-mass-spectrometry/",
        "mentions": [
          "state-of-charge",
          "reduction",
          "ec"
        ]
      }
    },
    {
      "id": "term:neutron-imaging-diffraction",
      "type": "Term",
      "label": "Neutron imaging and diffraction",
      "properties": {
        "id": "neutron-imaging-diffraction",
        "name": "Neutron imaging and diffraction",
        "aka": [
          "neutron radiography",
          "neutron diffraction",
          "neutron tomography"
        ],
        "section": "topic-analysis",
        "definition": "Methods using neutrons, which pass easily through steel cans but are strongly scattered or absorbed by lithium and hydrogen. Imaging shows electrolyte filling, gas and lithium distribution in whole cells; diffraction follows graphite staging and cathode phases in commercial cells while they cycle, and can catch lithium plating at low temperature.",
        "related": [
          "x-ray-diffraction",
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        "mentions": [
          "cathode",
          "graphite",
          "electrolyte",
          "electrolyte-filling"
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      }
    },
    {
      "id": "term:instrumented-cell",
      "type": "Term",
      "label": "Instrumented cell",
      "properties": {
        "id": "instrumented-cell",
        "name": "Instrumented cell",
        "aka": [
          "sensorised cell",
          "embedded sensors",
          "fibre Bragg grating",
          "FBG"
        ],
        "section": "topic-testing",
        "definition": "A cell built or modified with sensors inside — thermocouples in the jelly roll, optical fibres with Bragg gratings for temperature and strain, reference electrodes, pressure sensors — to measure what surface sensors miss. At high current the core can run several degrees hotter than the can, which only such cells show directly.",
        "related": [
          "temperature-sensor",
          "reference-electrode",
          "three-electrode-cell",
          "thermal-model",
          "jelly-roll"
        ],
        "url": "https://lemonergy.com/learn/glossary/instrumented-cell/",
        "mentions": []
      }
    },
    {
      "id": "term:dismantling",
      "type": "Term",
      "label": "Dismantling",
      "properties": {
        "id": "dismantling",
        "name": "Dismantling",
        "aka": [
          "disassembly",
          "pack disassembly"
        ],
        "section": "topic-recycling",
        "definition": "Taking a pack apart down to modules or cells to recover the casing, busbars, cables and electronics separately and to send only the cells on. It is still largely manual; robotic disassembly is held back by the variety of designs, glue and potting.",
        "related": [
          "deactivation",
          "design-for-recycling",
          "shredding",
          "remanufacturing"
        ],
        "url": "https://lemonergy.com/learn/glossary/dismantling/",
        "mentions": [
          "potting-compound"
        ]
      }
    },
    {
      "id": "reference:xiang-characterization",
      "type": "Reference",
      "label": "Advanced characterization techniques for solid state lithium battery research",
      "properties": {
        "title": "Advanced characterization techniques for solid state lithium battery research",
        "publisher": "Materials Today",
        "url": "https://doi.org/10.1016/j.mattod.2020.01.018",
        "type": "Review article",
        "scope": "X-ray, solid-state NMR and neutron methods in solid-state battery research.",
        "year": 2020,
        "authors": [
          "Yuxuan Xiang",
          "Xia Li",
          "Yongqiang Cheng",
          "Xueliang Sun",
          "Yong Yang"
        ],
        "accessed": "2026-10-27"
      }
    }
  ]
}