{
  "node": {
    "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": []
    }
  },
  "edges": [
    {
      "id": "edge:2725",
      "source": "term:post-mortem",
      "target": "topic:topic-analysis",
      "type": "belongsTo",
      "properties": {
        "sourceFile": "terms.json"
      }
    },
    {
      "id": "edge:2726",
      "source": "term:post-mortem",
      "target": "term:aging-mechanism",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:2727",
      "source": "term:post-mortem",
      "target": "term:scanning-electron-microscopy",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:2728",
      "source": "term:post-mortem",
      "target": "term:x-ray-diffraction",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:2729",
      "source": "term:post-mortem",
      "target": "term:differential-voltage-analysis",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:2730",
      "source": "term:post-mortem",
      "target": "term:nuclear-magnetic-resonance",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    }
  ],
  "neighbors": [
    {
      "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:aging-mechanism",
      "type": "Term",
      "label": "Aging mechanism",
      "properties": {
        "id": "aging-mechanism",
        "name": "Aging mechanism",
        "aka": [
          "degradation mode"
        ],
        "section": "topic-aging",
        "definition": "A specific physical or chemical process that degrades a cell — SEI growth, lithium plating, particle cracking, transition-metal dissolution. Mechanisms are grouped into three modes: loss of lithium inventory, loss of active material and resistance increase.",
        "related": [
          "loss-of-lithium-inventory",
          "loss-of-active-material",
          "impedance-rise",
          "aging"
        ],
        "lesson": "fundamentals/battery-aging/#where",
        "url": "https://lemonergy.com/learn/glossary/aging-mechanism/",
        "mentions": [
          "active-material",
          "sei",
          "lithium-plating",
          "particle-cracking",
          "transition-metal-dissolution"
        ]
      }
    },
    {
      "id": "term:scanning-electron-microscopy",
      "type": "Term",
      "label": "Scanning electron microscopy",
      "properties": {
        "id": "scanning-electron-microscopy",
        "name": "Scanning electron microscopy",
        "abbr": "SEM",
        "section": "topic-analysis",
        "definition": "Imaging a surface with a focused electron beam at magnifications far beyond light microscopy. In battery work it shows particle cracking, plated lithium and coating morphology; cross-sections show the layer structure of an electrode.",
        "related": [
          "post-mortem",
          "particle-cracking",
          "x-ray-diffraction"
        ],
        "url": "https://lemonergy.com/learn/glossary/scanning-electron-microscopy/",
        "mentions": [
          "electrode",
          "coating"
        ]
      }
    },
    {
      "id": "term:x-ray-diffraction",
      "type": "Term",
      "label": "X-ray diffraction",
      "properties": {
        "id": "x-ray-diffraction",
        "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",
          "post-mortem"
        ],
        "url": "https://lemonergy.com/learn/glossary/x-ray-diffraction/",
        "mentions": [
          "electrode",
          "operando-measurement"
        ]
      }
    },
    {
      "id": "term:differential-voltage-analysis",
      "type": "Term",
      "label": "Differential voltage analysis",
      "properties": {
        "id": "differential-voltage-analysis",
        "name": "Differential voltage analysis",
        "abbr": "DVA",
        "aka": [
          "dV/dQ"
        ],
        "section": "topic-state",
        "definition": "Plotting the derivative of voltage with respect to charge during a slow cycle. Its peaks mark electrode phase transitions, and how they shift between cycles separates lithium inventory loss from active-material loss without opening the cell.",
        "formula": "dV/dQ vs Q",
        "related": [
          "incremental-capacity-analysis",
          "loss-of-lithium-inventory",
          "loss-of-active-material",
          "phase-transition"
        ],
        "example": {
          "title": "Interpret a local slope",
          "text": "If voltage changes by 0.020 V over 0.10 Ah in a slowly measured region, the local slope is approximately 0.20 V/Ah. Comparing curves requires consistent current, temperature, sampling and preprocessing."
        },
        "url": "https://lemonergy.com/learn/glossary/differential-voltage-analysis/",
        "mentions": [
          "electrode"
        ]
      }
    },
    {
      "id": "term:nuclear-magnetic-resonance",
      "type": "Term",
      "label": "Nuclear magnetic resonance",
      "properties": {
        "id": "nuclear-magnetic-resonance",
        "name": "Nuclear magnetic resonance",
        "abbr": "NMR",
        "aka": [
          "solid-state NMR",
          "⁷Li NMR",
          "MAS NMR"
        ],
        "section": "topic-analysis",
        "definition": "Probing nuclei such as ⁷Li, ¹⁹F and ¹H in a strong magnetic field, where their resonance frequencies reveal their chemical surroundings. Solid-state ⁷Li NMR separates metallic lithium, shifted by about 250 ppm, from lithium in graphite or the SEI, so it can quantify plating even operando; solution NMR identifies electrolyte decomposition products.",
        "related": [
          "lithium-plating",
          "dead-lithium",
          "electrolyte-decomposition",
          "operando-measurement",
          "sei"
        ],
        "url": "https://lemonergy.com/learn/glossary/nuclear-magnetic-resonance/",
        "mentions": [
          "graphite",
          "electrolyte"
        ]
      }
    }
  ]
}