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        "aging-step",
        "first-cycle-loss",
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        "title": "Distinguish first finishing cycles",
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        "lede": "The steps that turn powders and foils into a finished cell, in production order.",
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      "label": "Solid–electrolyte interphase",
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        "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.",
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        "section": "topic-manufacturing",
        "definition": "Storing freshly formed cells for days to weeks, at room or elevated temperature, so the SEI stabilises and any cell with a latent short reveals itself through voltage drop. Not to be confused with aging as degradation over a cell’s life.",
        "related": [
          "formation",
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      "label": "First-cycle loss",
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        "name": "First-cycle loss",
        "aka": [
          "initial coulombic efficiency",
          "ICE"
        ],
        "section": "topic-manufacturing",
        "definition": "The lithium consumed in forming the SEI on the first charge, which never returns to the positive electrode: about 5–10 % of capacity for graphite and far more for silicon. Pre-lithiation is the way to pay this debt in advance.",
        "unit": "%",
        "related": [
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      "id": "term:cell-finishing",
      "type": "Term",
      "label": "Cell finishing",
      "properties": {
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        "name": "Cell finishing",
        "section": "topic-manufacturing",
        "definition": "The third phase of cell production: formation, degassing, aging and end-of-line testing. It is slow and ties up capital — cells sit for weeks — which is why shortening it is a major research goal.",
        "related": [
          "formation",
          "degassing",
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        "url": "https://lemonergy.com/learn/glossary/cell-finishing/",
        "mentions": []
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    {
      "id": "term:cell-production",
      "type": "Term",
      "label": "Cell production",
      "properties": {
        "id": "cell-production",
        "name": "Cell production",
        "section": "topic-manufacturing",
        "definition": "The three-phase process that turns powders and foils into finished cells: electrode making, cell assembly and cell finishing. Electrode making is a roll-to-roll chemical process; assembly is precision mechanics; finishing is electrochemistry that takes weeks.",
        "related": [
          "electrode-manufacturing",
          "cell-assembly",
          "cell-finishing",
          "gigafactory"
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        "url": "https://lemonergy.com/learn/glossary/cell-production/",
        "mentions": [
          "electrode"
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    },
    {
      "id": "lesson:fundamentals/cell-production/",
      "type": "Lesson",
      "label": "Lesson 3 · Cell production",
      "properties": {
        "url": "https://lemonergy.com/learn/fundamentals/cell-production/"
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    },
    {
      "id": "reference:liu-manufacturing",
      "type": "Reference",
      "label": "Current and future lithium-ion battery manufacturing",
      "properties": {
        "title": "Current and future lithium-ion battery manufacturing",
        "publisher": "iScience",
        "url": "https://doi.org/10.1016/j.isci.2021.102332",
        "type": "Review article",
        "scope": "Electrode preparation, cell assembly, formation and manufacturing trade-offs.",
        "year": 2021,
        "authors": [
          "Yangtao Liu",
          "Ruihan Zhang",
          "Jun Wang",
          "Yan Wang"
        ],
        "accessed": "2026-10-27"
      }
    }
  ]
}