{
  "node": {
    "id": "term:hard-carbon",
    "type": "Term",
    "label": "Hard carbon",
    "properties": {
      "id": "hard-carbon",
      "name": "Hard carbon",
      "section": "topic-components",
      "definition": "A disordered, non-graphitisable carbon used as the negative electrode of sodium-ion cells, where graphite barely works, and as a fast-charge additive in lithium-ion. Its open structure accepts ions without the strict layer spacing of graphite.",
      "related": [
        "sodium-ion",
        "graphite",
        "anode-active-material"
      ],
      "url": "https://lemonergy.com/learn/glossary/hard-carbon/",
      "mentions": [
        "electrode",
        "negative-electrode"
      ]
    }
  },
  "edges": [
    {
      "id": "edge:402",
      "source": "term:hard-carbon",
      "target": "topic:topic-components",
      "type": "belongsTo",
      "properties": {
        "sourceFile": "terms.json"
      }
    },
    {
      "id": "edge:403",
      "source": "term:hard-carbon",
      "target": "term:sodium-ion",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:404",
      "source": "term:hard-carbon",
      "target": "term:graphite",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:405",
      "source": "term:hard-carbon",
      "target": "term:anode-active-material",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:mentions/hard-carbon/electrode",
      "source": "term:hard-carbon",
      "target": "term:electrode",
      "type": "mentions",
      "properties": {
        "sourceFile": "terms.json",
        "method": "build_glossary.mention_index + mentions",
        "field": "definition",
        "meaning": "Text mention; not a causal claim"
      }
    },
    {
      "id": "edge:mentions/hard-carbon/negative-electrode",
      "source": "term:hard-carbon",
      "target": "term:negative-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": "topic:topic-components",
      "type": "Topic",
      "label": "Cell components and electrode materials",
      "properties": {
        "id": "topic-components",
        "name": "Cell components and electrode materials",
        "lede": "What a cell is physically made of — active materials, binders, additives, foils and tabs — and how its electrodes are put together.",
        "context": "Connect each material with its function.",
        "example": "Electrons travel through additive, foil and tab; ions use electrolyte and separator pathways.",
        "lesson_url": "https://lemonergy.com/learn/fundamentals/cell-anatomy/",
        "lesson_label": "Open cell anatomy"
      }
    },
    {
      "id": "term:sodium-ion",
      "type": "Term",
      "label": "Sodium-ion battery",
      "properties": {
        "id": "sodium-ion",
        "name": "Sodium-ion battery",
        "abbr": "Na-ion",
        "section": "topic-other-chemistries",
        "definition": "A cell built like a lithium-ion cell but shuttling sodium ions, usually between a hard-carbon negative electrode and a layered oxide or Prussian-blue positive. It uses no lithium, cobalt or copper, at the cost of lower energy density.",
        "related": [
          "hard-carbon",
          "lithium-ion",
          "energy-density",
          "stationary-storage",
          "seawater-battery"
        ],
        "url": "https://lemonergy.com/learn/glossary/sodium-ion/",
        "mentions": [
          "electrode",
          "negative-electrode",
          "cobalt",
          "layered-oxide"
        ]
      }
    },
    {
      "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:anode-active-material",
      "type": "Term",
      "label": "Anode active material",
      "properties": {
        "id": "anode-active-material",
        "name": "Anode active material",
        "abbr": "AAM",
        "section": "topic-components",
        "definition": "The lithium host in the negative electrode: natural or synthetic graphite in almost every lithium-ion cell today, sometimes blended with a few percent of silicon to raise capacity.",
        "related": [
          "active-material",
          "graphite",
          "silicon-anode",
          "hard-carbon",
          "lto"
        ],
        "url": "https://lemonergy.com/learn/glossary/anode-active-material/",
        "mentions": [
          "electrode",
          "negative-electrode",
          "synthetic-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: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"
        ],
        "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"
        ]
      }
    }
  ]
}