{
  "node": {
    "id": "term:dtd",
    "type": "Term",
    "label": "Ethylene sulfate",
    "properties": {
      "id": "dtd",
      "name": "Ethylene sulfate",
      "abbr": "DTD",
      "aka": [
        "1,3,2-dioxathiolane 2,2-dioxide",
        "DTD additive",
        "glycol sulfate"
      ],
      "section": "topic-electrolytes",
      "definition": "A cyclic sulfate, 1,3,2-dioxathiolane 2,2-dioxide, added to electrolytes at about 1–2 %, often together with vinylene carbonate. It is reduced on the negative electrode during formation, leaving a sulfur-containing SEI, and keeps cell impedance lower than VC alone would. It is used in both lithium-ion and sodium-ion electrolytes.",
      "related": [
        "electrolyte-additive",
        "vc",
        "sei",
        "formation",
        "impedance-rise",
        "lidfp"
      ],
      "url": "https://lemonergy.com/learn/glossary/dtd/",
      "mentions": [
        "impedance",
        "electrode",
        "negative-electrode"
      ]
    }
  },
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      "id": "edge:5769",
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      "type": "relatedTo",
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        "sourceFile": "terms.json",
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      "id": "edge:5770",
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        "meaning": "Related context; not a causal claim"
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      "id": "edge:5771",
      "source": "term:dtd",
      "target": "term:sei",
      "type": "relatedTo",
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        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
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    {
      "id": "edge:5772",
      "source": "term:dtd",
      "target": "term:formation",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
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      "id": "edge:5773",
      "source": "term:dtd",
      "target": "term:impedance-rise",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
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    {
      "id": "edge:5774",
      "source": "term:dtd",
      "target": "term:lidfp",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
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    },
    {
      "id": "edge:mentions/dtd/impedance",
      "source": "term:dtd",
      "target": "term:impedance",
      "type": "mentions",
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      "id": "edge:mentions/dtd/electrode",
      "source": "term:dtd",
      "target": "term:electrode",
      "type": "mentions",
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        "sourceFile": "terms.json",
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    {
      "id": "topic:topic-electrolytes",
      "type": "Topic",
      "label": "Electrolytes and separators",
      "properties": {
        "id": "topic-electrolytes",
        "name": "Electrolytes and separators",
        "lede": "What sits between the electrodes: liquid, gel and solid electrolytes, their salts, solvents and additives, and the separator that keeps the electrodes apart.",
        "context": "Connect transport with electronic isolation.",
        "example": "Greater liquid uptake may improve wetting while changing mechanical behavior. Several properties define separator performance.",
        "lesson_url": "https://lemonergy.com/learn/fundamentals/cell-anatomy/",
        "lesson_label": "Open cell anatomy"
      }
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    {
      "id": "term:electrolyte-additive",
      "type": "Term",
      "label": "Electrolyte additive",
      "properties": {
        "id": "electrolyte-additive",
        "name": "Electrolyte additive",
        "aka": [
          "VC",
          "FEC"
        ],
        "section": "topic-electrolytes",
        "definition": "A compound added to the electrolyte at a few percent to improve one property — vinylene carbonate and fluoroethylene carbonate build a tougher SEI, others suppress gassing or overcharge. Additive packages are among a cell maker’s closest secrets.",
        "related": [
          "electrolyte",
          "sei",
          "formation",
          "gas-generation",
          "libob"
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        "url": "https://lemonergy.com/learn/glossary/electrolyte-additive/",
        "mentions": [
          "overcharge",
          "vc",
          "fec"
        ]
      }
    },
    {
      "id": "term:vc",
      "type": "Term",
      "label": "Vinylene carbonate",
      "properties": {
        "id": "vc",
        "name": "Vinylene carbonate",
        "abbr": "VC",
        "section": "topic-electrolytes",
        "definition": "The most common SEI-forming additive, used at 1–3 %. It is reduced before the solvent on the first charge and polymerises into a thinner, more flexible SEI that lengthens cycle life.",
        "related": [
          "electrolyte-additive",
          "sei",
          "fec",
          "formation"
        ],
        "url": "https://lemonergy.com/learn/glossary/vc/",
        "mentions": [
          "cycle-life"
        ]
      }
    },
    {
      "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",
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        "url": "https://lemonergy.com/learn/glossary/sei/",
        "mentions": [
          "electrode",
          "graphite",
          "electrolyte"
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    },
    {
      "id": "term:formation",
      "type": "Term",
      "label": "Formation",
      "properties": {
        "id": "formation",
        "name": "Formation",
        "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"
        ],
        "lesson": "fundamentals/cell-production/#finishing",
        "example": {
          "title": "Distinguish first finishing cycles",
          "text": "Initial controlled cycles are a cell-finishing operation; their purpose and observations differ from later customer charging."
        },
        "url": "https://lemonergy.com/learn/glossary/formation/",
        "mentions": [
          "cell-production"
        ]
      }
    },
    {
      "id": "term:impedance-rise",
      "type": "Term",
      "label": "Impedance rise",
      "properties": {
        "id": "impedance-rise",
        "name": "Impedance rise",
        "aka": [
          "resistance growth",
          "power fade"
        ],
        "section": "topic-aging",
        "definition": "An increase in a cell’s internal resistance as it ages. It costs voltage under load and therefore power, even while the stored charge is still there.",
        "related": [
          "internal-resistance",
          "sei",
          "cei",
          "state-of-power",
          "state-of-health"
        ],
        "lesson": "fundamentals/battery-aging/#crystals",
        "url": "https://lemonergy.com/learn/glossary/impedance-rise/",
        "mentions": [
          "closed-circuit-voltage"
        ]
      }
    },
    {
      "id": "term:lidfp",
      "type": "Term",
      "label": "Lithium difluorophosphate",
      "properties": {
        "id": "lidfp",
        "name": "Lithium difluorophosphate",
        "abbr": "LiDFP",
        "aka": [
          "LiPO₂F₂"
        ],
        "section": "topic-electrolytes",
        "definition": "A salt-type additive, LiPO₂F₂, used at around 1 % because it dissolves only sparingly in carbonate solvents. It forms thin phosphate-rich films on both electrodes that lower interfacial resistance, improving low-temperature power and high-voltage cycling. Small amounts also form naturally when LiPF₆ meets traces of water.",
        "related": [
          "electrolyte-additive",
          "lipf6",
          "sei",
          "cei",
          "dtd",
          "lithium-salt"
        ],
        "url": "https://lemonergy.com/learn/glossary/lidfp/",
        "mentions": []
      }
    },
    {
      "id": "term:impedance",
      "type": "Term",
      "label": "Impedance",
      "properties": {
        "id": "impedance",
        "name": "Impedance",
        "abbr": "Z",
        "section": "topic-units",
        "definition": "The frequency-dependent generalisation of resistance, with a magnitude and a phase. A cell’s impedance separates ohmic, charge-transfer and diffusion contributions that a single DC resistance lumps together.",
        "unit": "Ω",
        "related": [
          "internal-resistance",
          "electrochemical-impedance-spectroscopy",
          "nyquist-plot"
        ],
        "url": "https://lemonergy.com/learn/glossary/impedance/",
        "mentions": [
          "diffusion"
        ]
      }
    },
    {
      "id": "term:electrode",
      "type": "Term",
      "label": "Electrode",
      "properties": {
        "id": "electrode",
        "name": "Electrode",
        "section": "topic-components",
        "definition": "A solid conductor where the cell’s reaction happens, in contact with the electrolyte. A lithium-ion cell has a negative electrode and a positive electrode, each a porous coating on a metal foil.",
        "related": [
          "negative-electrode",
          "positive-electrode",
          "porous-electrode",
          "current-collector"
        ],
        "lesson": "fundamentals/cell-anatomy/#components",
        "example": {
          "title": "Two transport paths",
          "text": "Electrons need connected solid paths to the collector; ions need electrolyte paths to reaction sites. More of one constituent displaces others at fixed volume."
        },
        "url": "https://lemonergy.com/learn/glossary/electrode/",
        "mentions": [
          "electrolyte",
          "coating"
        ]
      }
    },
    {
      "id": "term:negative-electrode",
      "type": "Term",
      "label": "Negative electrode",
      "properties": {
        "id": "negative-electrode",
        "name": "Negative electrode",
        "section": "topic-components",
        "definition": "The electrode at the lower potential, usually graphite on copper foil in a lithium-ion cell. It holds the lithium when the cell is charged and releases it on discharge, and industry calls it the anode.",
        "related": [
          "anode",
          "graphite",
          "positive-electrode",
          "copper-foil"
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        "lesson": "fundamentals/cell-anatomy/#anode-cathode",
        "example": {
          "title": "Keep the polarity name",
          "text": "Graphite remains the negative electrode during charge and discharge, while the anode/cathode reaction labels change with operating direction."
        },
        "url": "https://lemonergy.com/learn/glossary/negative-electrode/",
        "mentions": [
          "electrode"
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    }
  ]
}