{
  "node": {
    "id": "term:half-reaction",
    "type": "Term",
    "label": "Half-reaction",
    "properties": {
      "id": "half-reaction",
      "name": "Half-reaction",
      "aka": [
        "half-cell reaction"
      ],
      "section": "topic-electrochemistry",
      "definition": "The oxidation or reduction occurring at one electrode, written on its own with electrons shown explicitly. The cell reaction is the sum of its two half-reactions, and the cell voltage is the difference of their potentials.",
      "related": [
        "redox-reaction",
        "electrode-potential",
        "half-cell",
        "cell-voltage"
      ],
      "lesson": "labs/battery-materials-lab/#bml-liion-mechanism",
      "url": "https://lemonergy.com/learn/glossary/half-reaction/",
      "mentions": [
        "electrode",
        "oxidation",
        "reduction"
      ]
    }
  },
  "edges": [
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      "id": "edge:1826",
      "source": "term:half-reaction",
      "target": "topic:topic-electrochemistry",
      "type": "belongsTo",
      "properties": {
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      }
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    {
      "id": "edge:1827",
      "source": "term:half-reaction",
      "target": "term:redox-reaction",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:1828",
      "source": "term:half-reaction",
      "target": "term:electrode-potential",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:1829",
      "source": "term:half-reaction",
      "target": "term:half-cell",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:1830",
      "source": "term:half-reaction",
      "target": "term:cell-voltage",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:mentions/half-reaction/electrode",
      "source": "term:half-reaction",
      "target": "term:electrode",
      "type": "mentions",
      "properties": {
        "sourceFile": "terms.json",
        "method": "build_glossary.mention_index + mentions",
        "field": "definition",
        "meaning": "Text mention; not a causal claim"
      }
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    {
      "id": "edge:mentions/half-reaction/oxidation",
      "source": "term:half-reaction",
      "target": "term:oxidation",
      "type": "mentions",
      "properties": {
        "sourceFile": "terms.json",
        "method": "build_glossary.mention_index + mentions",
        "field": "definition",
        "meaning": "Text mention; not a causal claim"
      }
    },
    {
      "id": "edge:mentions/half-reaction/reduction",
      "source": "term:half-reaction",
      "target": "term:reduction",
      "type": "mentions",
      "properties": {
        "sourceFile": "terms.json",
        "method": "build_glossary.mention_index + mentions",
        "field": "definition",
        "meaning": "Text mention; not a causal claim"
      }
    },
    {
      "id": "edge:1834",
      "source": "term:half-reaction",
      "target": "lesson:labs/battery-materials-lab/",
      "type": "explainedIn",
      "properties": {
        "sourceFile": "terms.json",
        "url": "https://lemonergy.com/learn/labs/battery-materials-lab/#bml-liion-mechanism"
      }
    }
  ],
  "neighbors": [
    {
      "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"
      }
    },
    {
      "id": "term:redox-reaction",
      "type": "Term",
      "label": "Redox reaction",
      "properties": {
        "id": "redox-reaction",
        "name": "Redox reaction",
        "section": "topic-electrochemistry",
        "definition": "A reaction in which electrons move from one species to another: one is oxidised, the other reduced. A battery separates the two halves onto two electrodes so the electrons must travel through the external circuit.",
        "related": [
          "oxidation",
          "reduction",
          "half-reaction",
          "electrode-potential",
          "galvanic-cell"
        ],
        "lesson": "labs/battery-materials-lab/#bml-aqueous-mechanism",
        "url": "https://lemonergy.com/learn/glossary/redox-reaction/",
        "mentions": []
      }
    },
    {
      "id": "term:electrode-potential",
      "type": "Term",
      "label": "Electrode potential",
      "properties": {
        "id": "electrode-potential",
        "name": "Electrode potential",
        "section": "topic-electrochemistry",
        "definition": "The potential of an electrode relative to a reference, which for lithium-ion work is lithium metal in the same electrolyte, written as V vs Li/Li⁺. Graphite sits near 0.1 V and layered oxides near 3.7–4.3 V on this scale.",
        "unit": "V vs Li/Li⁺",
        "related": [
          "standard-potential",
          "cell-voltage",
          "reference-electrode",
          "half-reaction"
        ],
        "lesson": "labs/battery-materials-lab/#battery-materials-lab",
        "url": "https://lemonergy.com/learn/glossary/electrode-potential/",
        "mentions": [
          "electrode",
          "graphite",
          "electrolyte"
        ]
      }
    },
    {
      "id": "term:half-cell",
      "type": "Term",
      "label": "Half-cell",
      "properties": {
        "id": "half-cell",
        "name": "Half-cell",
        "section": "topic-testing",
        "definition": "A test cell with the electrode under study against lithium metal, so the measured potential is that electrode’s alone. It is how a new material’s capacity and voltage are first measured, usually in coin-cell format.",
        "related": [
          "coin-cell",
          "full-cell",
          "electrode-potential",
          "lithium-metal-anode"
        ],
        "url": "https://lemonergy.com/learn/glossary/half-cell/",
        "mentions": [
          "electrode"
        ]
      }
    },
    {
      "id": "term:cell-voltage",
      "type": "Term",
      "label": "Cell voltage",
      "properties": {
        "id": "cell-voltage",
        "name": "Cell voltage",
        "aka": [
          "electromotive force",
          "EMF"
        ],
        "section": "topic-electrochemistry",
        "definition": "The difference between the positive and negative electrode potentials at equilibrium: for NMC against graphite about 3.7 V. It is set by the chemistry, and the difference in Gibbs free energy of the cell reaction per unit charge.",
        "formula": "E = E₊ − E₋ = −ΔG / nF",
        "unit": "V",
        "related": [
          "electrode-potential",
          "gibbs-free-energy",
          "open-circuit-voltage",
          "nominal-voltage"
        ],
        "example": {
          "title": "Subtract equilibrium electrode potentials",
          "text": "If two illustrative electrode potentials are 4.0 V and 0.2 V versus the same reference, their equilibrium cell voltage is 3.8 V. Under load, resistance and polarization change the measured terminal voltage."
        },
        "url": "https://lemonergy.com/learn/glossary/cell-voltage/",
        "mentions": [
          "electrode",
          "negative-electrode",
          "graphite"
        ]
      }
    },
    {
      "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:oxidation",
      "type": "Term",
      "label": "Oxidation",
      "properties": {
        "id": "oxidation",
        "name": "Oxidation",
        "section": "topic-electrochemistry",
        "definition": "Loss of electrons by a species. On discharge the negative electrode is oxidised as lithium leaves it as Li⁺, which is why that electrode is called the anode.",
        "related": [
          "reduction",
          "anode",
          "redox-reaction"
        ],
        "url": "https://lemonergy.com/learn/glossary/oxidation/",
        "mentions": [
          "electrode",
          "negative-electrode"
        ]
      }
    },
    {
      "id": "term:reduction",
      "type": "Term",
      "label": "Reduction",
      "properties": {
        "id": "reduction",
        "name": "Reduction",
        "section": "topic-electrochemistry",
        "definition": "Gain of electrons by a species. On discharge the positive electrode is reduced as it takes up lithium ions and electrons, which is why it is called the cathode.",
        "related": [
          "oxidation",
          "cathode",
          "redox-reaction"
        ],
        "url": "https://lemonergy.com/learn/glossary/reduction/",
        "mentions": [
          "electrode",
          "positive-electrode"
        ]
      }
    },
    {
      "id": "lesson:labs/battery-materials-lab/",
      "type": "Lesson",
      "label": "Battery materials lab",
      "properties": {
        "url": "https://lemonergy.com/learn/labs/battery-materials-lab/"
      }
    }
  ]
}