{
  "node": {
    "id": "term:x-ray-photoelectron-spectroscopy",
    "type": "Term",
    "label": "X-ray photoelectron spectroscopy",
    "properties": {
      "id": "x-ray-photoelectron-spectroscopy",
      "name": "X-ray photoelectron spectroscopy",
      "abbr": "XPS",
      "aka": [
        "ESCA",
        "photoelectron spectroscopy"
      ],
      "section": "topic-analysis",
      "definition": "Shining X-rays on a surface and measuring the energies of the electrons knocked out, which identify each element and its chemical bonding in the top few nanometres. It is the main tool for SEI and CEI composition — LiF, Li₂CO₃, organic carbonates — and, combined with argon-ion sputtering, for depth profiles.",
      "related": [
        "sei",
        "cei",
        "time-of-flight-sims",
        "post-mortem",
        "fourier-transform-infrared-spectroscopy"
      ],
      "url": "https://lemonergy.com/learn/glossary/x-ray-photoelectron-spectroscopy/",
      "mentions": [
        "lithium-carbonate"
      ]
    }
  },
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      "id": "edge:5550",
      "source": "term:x-ray-photoelectron-spectroscopy",
      "target": "term:sei",
      "type": "relatedTo",
      "properties": {
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        "meaning": "Related context; not a causal claim"
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      "target": "term:cei",
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      "id": "edge:5553",
      "source": "term:x-ray-photoelectron-spectroscopy",
      "target": "term:post-mortem",
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      "id": "edge:5554",
      "source": "term:x-ray-photoelectron-spectroscopy",
      "target": "term:fourier-transform-infrared-spectroscopy",
      "type": "relatedTo",
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        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
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      "id": "edge:mentions/x-ray-photoelectron-spectroscopy/lithium-carbonate",
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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.",
        "lesson_url": "https://lemonergy.com/learn/labs/battery-materials-lab/",
        "lesson_label": "Open materials lab"
      }
    },
    {
      "id": "term:sei",
      "type": "Term",
      "label": "Solid–electrolyte interphase",
      "properties": {
        "id": "sei",
        "name": "Solid–electrolyte interphase",
        "abbr": "SEI",
        "section": "topic-aging",
        "definition": "A film of electrolyte reaction products on the negative-electrode particles — graphite, and also silicon or lithium metal. It protects the electrode from further reaction but grows slowly for the whole life of the cell, consuming cyclable lithium.",
        "related": [
          "passivation",
          "formation",
          "calendar-aging",
          "loss-of-lithium-inventory",
          "cei"
        ],
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        "url": "https://lemonergy.com/learn/glossary/sei/",
        "mentions": [
          "electrode",
          "graphite",
          "electrolyte"
        ]
      }
    },
    {
      "id": "term:cei",
      "type": "Term",
      "label": "Cathode–electrolyte interphase",
      "properties": {
        "id": "cei",
        "name": "Cathode–electrolyte interphase",
        "abbr": "CEI",
        "section": "topic-aging",
        "definition": "The counterpart of the SEI on the positive electrode: a thin layer of electrolyte oxidation products on the oxide surface. It is thinner and less stable than the SEI, and its growth contributes to impedance rise, especially at high voltage.",
        "related": [
          "sei",
          "electrolyte-decomposition",
          "impedance-rise",
          "high-nickel"
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        "mentions": [
          "impedance",
          "electrode",
          "positive-electrode",
          "electrolyte",
          "oxidation"
        ]
      }
    },
    {
      "id": "term:time-of-flight-sims",
      "type": "Term",
      "label": "Time-of-flight secondary ion mass spectrometry",
      "properties": {
        "id": "time-of-flight-sims",
        "name": "Time-of-flight secondary ion mass spectrometry",
        "abbr": "ToF-SIMS",
        "aka": [
          "SIMS",
          "secondary ion mass spectrometry"
        ],
        "section": "topic-analysis",
        "definition": "Sputtering the outermost atomic layers of a sample with a pulsed ion beam and weighing the ejected ions by how long they take to reach the detector. It detects every element, lithium and hydrogen included, at parts-per-million levels, and maps SEI fragments across a surface and, with a second sputter beam, in depth.",
        "related": [
          "x-ray-photoelectron-spectroscopy",
          "sei",
          "post-mortem",
          "transition-metal-dissolution"
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        "url": "https://lemonergy.com/learn/glossary/time-of-flight-sims/",
        "mentions": []
      }
    },
    {
      "id": "term:post-mortem",
      "type": "Term",
      "label": "Post-mortem analysis",
      "properties": {
        "id": "post-mortem",
        "name": "Post-mortem analysis",
        "aka": [
          "teardown"
        ],
        "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",
          "x-ray-diffraction",
          "differential-voltage-analysis",
          "nuclear-magnetic-resonance"
        ],
        "url": "https://lemonergy.com/learn/glossary/post-mortem/",
        "mentions": []
      }
    },
    {
      "id": "term:fourier-transform-infrared-spectroscopy",
      "type": "Term",
      "label": "Fourier-transform infrared spectroscopy",
      "properties": {
        "id": "fourier-transform-infrared-spectroscopy",
        "name": "Fourier-transform infrared spectroscopy",
        "abbr": "FTIR",
        "aka": [
          "infrared spectroscopy",
          "IR spectroscopy",
          "ATR-FTIR"
        ],
        "section": "topic-analysis",
        "definition": "Identifying chemical bonds from the infrared wavelengths a sample absorbs. Battery labs use it to fingerprint electrolyte solvents and their ratios, organic SEI species such as lithium alkyl carbonates, and binders; the attenuated-total-reflectance mode probes electrode surfaces directly, and gas cells analyse vent gas online.",
        "related": [
          "x-ray-photoelectron-spectroscopy",
          "sei",
          "electrolyte",
          "electrolyte-decomposition",
          "off-gas"
        ],
        "url": "https://lemonergy.com/learn/glossary/fourier-transform-infrared-spectroscopy/",
        "mentions": [
          "electrode"
        ]
      }
    },
    {
      "id": "term:lithium-carbonate",
      "type": "Term",
      "label": "Lithium carbonate",
      "properties": {
        "id": "lithium-carbonate",
        "name": "Lithium carbonate",
        "abbr": "Li₂CO₃",
        "aka": [
          "LCE",
          "lithium carbonate equivalent"
        ],
        "section": "topic-sustainability",
        "definition": "The commodity form in which most lithium is traded and the lithium source for LFP and mid-nickel cathodes. Lithium carbonate equivalent, LCE, is the unit the industry uses to count lithium supply whatever its chemical form.",
        "related": [
          "lithium-hydroxide",
          "brine",
          "spodumene",
          "calcination",
          "lithium"
        ],
        "url": "https://lemonergy.com/learn/glossary/lithium-carbonate/",
        "mentions": []
      }
    }
  ]
}