{
  "node": {
    "id": "term:electrochemical-stability-window",
    "type": "Term",
    "label": "Electrochemical stability window",
    "properties": {
      "id": "electrochemical-stability-window",
      "name": "Electrochemical stability window",
      "section": "topic-electrochemistry",
      "definition": "The potential range within which an electrolyte is neither reduced nor oxidised. Carbonate electrolytes are only stable from about 1 V to 4.3 V vs Li/Li⁺; graphite operates below that, which is why the SEI, not thermodynamics, keeps the cell alive.",
      "unit": "V",
      "related": [
        "electrolyte-decomposition",
        "sei",
        "voltage-window",
        "lnmo",
        "homo-lumo"
      ],
      "url": "https://lemonergy.com/learn/glossary/electrochemical-stability-window/",
      "mentions": [
        "graphite",
        "electrolyte"
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    }
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  "edges": [
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      "source": "term:electrochemical-stability-window",
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    {
      "id": "edge:1943",
      "source": "term:electrochemical-stability-window",
      "target": "term:electrolyte-decomposition",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
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      "id": "edge:1944",
      "source": "term:electrochemical-stability-window",
      "target": "term:sei",
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      "id": "edge:1945",
      "source": "term:electrochemical-stability-window",
      "target": "term:voltage-window",
      "type": "relatedTo",
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        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
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      "id": "edge:1946",
      "source": "term:electrochemical-stability-window",
      "target": "term:lnmo",
      "type": "relatedTo",
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        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
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      "id": "edge:1947",
      "source": "term:electrochemical-stability-window",
      "target": "term:homo-lumo",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
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    },
    {
      "id": "edge:mentions/electrochemical-stability-window/graphite",
      "source": "term:electrochemical-stability-window",
      "target": "term:graphite",
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    {
      "id": "topic:topic-electrochemistry",
      "type": "Topic",
      "label": "Electrochemistry fundamentals",
      "properties": {
        "id": "topic-electrochemistry",
        "name": "Electrochemistry fundamentals",
        "lede": "The reactions and potentials that make a cell a battery.",
        "context": "Connect reaction sites and transport paths.",
        "example": "A circuit can predict terminal voltage while leaving electrode potentials and reaction kinetics unresolved.",
        "lesson_url": "https://lemonergy.com/learn/fundamentals/cell-anatomy/",
        "lesson_label": "Open cell anatomy"
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    {
      "id": "term:electrolyte-decomposition",
      "type": "Term",
      "label": "Electrolyte decomposition",
      "properties": {
        "id": "electrolyte-decomposition",
        "name": "Electrolyte decomposition",
        "section": "topic-aging",
        "definition": "Reduction of the electrolyte at the negative electrode and oxidation at the positive, outside its stability window. A little is useful — it builds the SEI — but continued decomposition consumes lithium, dries the cell and makes gas.",
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          "cei",
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          "electrolyte-dry-out"
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          "electrolyte",
          "oxidation",
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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",
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          "cei"
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        "url": "https://lemonergy.com/learn/glossary/sei/",
        "mentions": [
          "electrode",
          "graphite",
          "electrolyte"
        ]
      }
    },
    {
      "id": "term:voltage-window",
      "type": "Term",
      "label": "Voltage window",
      "properties": {
        "id": "voltage-window",
        "name": "Voltage window",
        "aka": [
          "operating voltage range"
        ],
        "section": "topic-ratings",
        "definition": "The range between a cell’s lower and upper cutoff voltages, such as 2.5–4.2 V for an NMC/graphite cell. Staying inside it is what keeps the electrodes and electrolyte from degrading quickly.",
        "unit": "V",
        "related": [
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          "electrochemical-stability-window"
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        "url": "https://lemonergy.com/learn/glossary/voltage-window/",
        "mentions": [
          "graphite",
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    {
      "id": "term:lnmo",
      "type": "Term",
      "label": "LNMO",
      "properties": {
        "id": "lnmo",
        "name": "LNMO",
        "aka": [
          "high-voltage spinel"
        ],
        "section": "topic-chemistries",
        "definition": "A nickel-doped manganese spinel, LiNi₀.₅Mn₁.₅O₄, that works at about 4.7 V and contains no cobalt. Its high voltage stresses today’s electrolytes, which is the main obstacle to commercial use.",
        "related": [
          "lmo",
          "electrochemical-stability-window",
          "electrolyte-decomposition"
        ],
        "url": "https://lemonergy.com/learn/glossary/lnmo/",
        "mentions": [
          "cobalt",
          "manganese"
        ]
      }
    },
    {
      "id": "term:homo-lumo",
      "type": "Term",
      "label": "HOMO–LUMO gap",
      "properties": {
        "id": "homo-lumo",
        "name": "HOMO–LUMO gap",
        "aka": [
          "HOMO",
          "LUMO",
          "frontier orbitals",
          "highest occupied molecular orbital",
          "lowest unoccupied molecular orbital"
        ],
        "section": "topic-electrochemistry",
        "definition": "The energy gap between a molecule’s highest occupied and lowest unoccupied orbitals, used to screen electrolyte components. A solvent whose LUMO lies below the negative electrode’s Fermi level is reduced, and one whose HOMO lies above the positive electrode’s is oxidised; additives such as vinylene carbonate are chosen to reduce before the main solvent and build the SEI.",
        "related": [
          "electrochemical-stability-window",
          "sei",
          "electrolyte-additive",
          "vc",
          "electrolyte-decomposition"
        ],
        "url": "https://lemonergy.com/learn/glossary/homo-lumo/",
        "mentions": [
          "electrode",
          "negative-electrode",
          "positive-electrode",
          "electrolyte"
        ]
      }
    },
    {
      "id": "term:graphite",
      "type": "Term",
      "label": "Graphite",
      "properties": {
        "id": "graphite",
        "name": "Graphite",
        "section": "topic-components",
        "definition": "Layered carbon, the negative active material of nearly all lithium-ion cells. Lithium intercalates between its layers up to LiC₆, a theoretical 372 mAh/g, at a potential about 0.1 V above lithium metal.",
        "related": [
          "anode-active-material",
          "intercalation",
          "natural-graphite",
          "synthetic-graphite",
          "lithium-plating"
        ],
        "lesson": "fundamentals/cell-anatomy/#components",
        "example": {
          "title": "Compare matching mass bases",
          "text": "A graphite value per gram of active material cannot be directly compared with a value including binder, additive and foil."
        },
        "url": "https://lemonergy.com/learn/glossary/graphite/",
        "mentions": [
          "milliampere-hour",
          "active-material"
        ]
      }
    },
    {
      "id": "term:electrolyte",
      "type": "Term",
      "label": "Electrolyte",
      "properties": {
        "id": "electrolyte",
        "name": "Electrolyte",
        "section": "topic-electrolytes",
        "definition": "The ion-conducting medium between the electrodes. In a liquid-electrolyte cell it fills the pores of both electrodes and the separator, so it is not a separate structural layer.",
        "related": [
          "lithium-salt",
          "carbonate-solvent",
          "electrolyte-additive",
          "ionic-conductivity",
          "solid-electrolyte",
          "ionic-liquid-electrolyte"
        ],
        "lesson": "fundamentals/cell-architecture/#electrolyte",
        "example": {
          "title": "Ions and electrons",
          "text": "Electrolyte carries ions between electrodes; the external circuit carries electrons. The two paths serve different roles."
        },
        "url": "https://lemonergy.com/learn/glossary/electrolyte/",
        "mentions": [
          "separator"
        ]
      }
    },
    {
      "id": "reference:xu-electrolytes",
      "type": "Reference",
      "label": "Electrolytes and Interphases in Li-Ion Batteries and Beyond",
      "properties": {
        "title": "Electrolytes and Interphases in Li-Ion Batteries and Beyond",
        "publisher": "Chemical Reviews",
        "url": "https://doi.org/10.1021/cr500003w",
        "type": "Review article",
        "scope": "Electrolyte salts, solvents, additives and electrode interphases.",
        "year": 2014,
        "authors": [
          "Kang Xu"
        ],
        "accessed": "2026-10-27"
      }
    }
  ]
}