{
  "node": {
    "id": "term:aging-step",
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    "label": "Aging (production)",
    "properties": {
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      "name": "Aging (production)",
      "aka": [
        "high-temperature aging",
        "storage step"
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      "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",
        "k-value",
        "cell-finishing",
        "aging"
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        "sei"
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      "source": "term:aging-step",
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      "id": "topic:topic-manufacturing",
      "type": "Topic",
      "label": "Manufacturing",
      "properties": {
        "id": "topic-manufacturing",
        "name": "Manufacturing",
        "lede": "The steps that turn powders and foils into a finished cell, in production order.",
        "context": "Place operations and quality checks in process order.",
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        "section": "topic-manufacturing",
        "definition": "The first controlled charge and discharge cycles of a newly assembled cell, during which the SEI forms. It is part of cell production, before aging and grading.",
        "related": [
          "sei",
          "degassing",
          "aging-step",
          "first-cycle-loss",
          "cell-finishing"
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        "example": {
          "title": "Distinguish first finishing cycles",
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        "url": "https://lemonergy.com/learn/glossary/formation/",
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          "OCV drop rate"
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        "section": "topic-manufacturing",
        "definition": "The rate at which a cell’s open-circuit voltage falls during the production aging step, in millivolts per day. A high K-value signals an internal short or contamination, and such cells are scrapped before shipment.",
        "unit": "mV/day",
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        "mentions": []
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      "id": "term:cell-finishing",
      "type": "Term",
      "label": "Cell finishing",
      "properties": {
        "id": "cell-finishing",
        "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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        "mentions": []
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    {
      "id": "term:aging",
      "type": "Term",
      "label": "Aging",
      "properties": {
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        "name": "Aging",
        "aka": [
          "degradation"
        ],
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        "definition": "The gradual, irreversible change in a cell’s capacity, resistance and safety margins over time and use. It is the sum of many chemical and mechanical mechanisms, each driven by temperature, state of charge, current and cycle depth.",
        "related": [
          "calendar-aging",
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        "url": "https://lemonergy.com/learn/glossary/aging/",
        "mentions": [
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      }
    },
    {
      "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"
        ],
        "lesson": "fundamentals/battery-aging/#sei",
        "url": "https://lemonergy.com/learn/glossary/sei/",
        "mentions": [
          "electrode",
          "graphite",
          "electrolyte"
        ]
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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/"
      }
    },
    {
      "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"
      }
    }
  ]
}