{
  "node": {
    "id": "term:heat-pipe",
    "type": "Term",
    "label": "Heat pipe",
    "properties": {
      "id": "heat-pipe",
      "name": "Heat pipe",
      "aka": [
        "vapour chamber"
      ],
      "section": "topic-thermal",
      "definition": "A sealed tube holding a little working fluid that evaporates at the hot end, condenses at the cold end and returns through a wick. It moves heat with an effective conductivity many times that of copper and little temperature drop. Common in electronics, it has been studied for spreading heat along cells, but packs still rely on cooling plates.",
      "related": [
        "heat-sink",
        "thermal-conductivity",
        "cooling-plate",
        "passive-thermal-management"
      ],
      "url": "https://lemonergy.com/learn/glossary/heat-pipe/",
      "mentions": []
    }
  },
  "edges": [
    {
      "id": "edge:4756",
      "source": "term:heat-pipe",
      "target": "topic:topic-thermal",
      "type": "belongsTo",
      "properties": {
        "sourceFile": "terms.json"
      }
    },
    {
      "id": "edge:4757",
      "source": "term:heat-pipe",
      "target": "term:heat-sink",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:4758",
      "source": "term:heat-pipe",
      "target": "term:thermal-conductivity",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:4759",
      "source": "term:heat-pipe",
      "target": "term:cooling-plate",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:4760",
      "source": "term:heat-pipe",
      "target": "term:passive-thermal-management",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    }
  ],
  "neighbors": [
    {
      "id": "topic:topic-thermal",
      "type": "Topic",
      "label": "Thermal management and heat transfer",
      "properties": {
        "id": "topic-thermal",
        "name": "Thermal management and heat transfer",
        "lede": "How heat is made, moved and removed in cells and packs, and the hardware that keeps a battery at the right temperature.",
        "context": "Select spatial detail for the question.",
        "example": "Equal total heat in different layouts can produce different gradients. Average temperature can miss a hot spot.",
        "lesson_url": "https://lemonergy.com/learn/fundamentals/battery-aging/",
        "lesson_label": "Open temperature and aging"
      }
    },
    {
      "id": "term:heat-sink",
      "type": "Term",
      "label": "Heat sink",
      "properties": {
        "id": "heat-sink",
        "name": "Heat sink",
        "aka": [
          "fins",
          "cooling fins",
          "finned heat sink"
        ],
        "section": "topic-thermal",
        "definition": "A metal body, often extruded aluminium with fins, that draws heat from a component and enlarges the surface it can lose that heat from. Fins multiply the area for convection to air; in batteries heat sinks serve air-cooled cell blocks and, above all, the balancing resistors and power switches of the BMS and DC/DC converter.",
        "related": [
          "heat-transfer-coefficient",
          "radiator",
          "passive-thermal-management",
          "cell-balancing",
          "heat-pipe"
        ],
        "url": "https://lemonergy.com/learn/glossary/heat-sink/",
        "mentions": [
          "bms",
          "dc-dc-converter",
          "heat-transfer-modes"
        ]
      }
    },
    {
      "id": "term:thermal-conductivity",
      "type": "Term",
      "label": "Thermal conductivity",
      "properties": {
        "id": "thermal-conductivity",
        "name": "Thermal conductivity",
        "abbr": "k",
        "aka": [
          "λ",
          "through-plane conductivity",
          "in-plane conductivity"
        ],
        "section": "topic-thermal",
        "definition": "How readily a material conducts heat: the heat flux per unit temperature gradient. Cells are strongly anisotropic — around 25–45 W/(m·K) in-plane, along the metal foils, but below 1 W/(m·K) through-plane, across separators and coatings — so the side a cell is cooled from decides how hot its core runs.",
        "formula": "q″ = −k·dT/dx",
        "unit": "W/(m·K)",
        "related": [
          "thermal-resistance",
          "thermal-diffusivity",
          "thermal-characterisation",
          "thermal-interface-material",
          "biot-number",
          "thermal-model"
        ],
        "example": {
          "title": "Calculate a slab heat flow",
          "text": "An illustrative 2 mm layer with k = 1 W/(m·K), area 0.01 m² and a 10 K temperature difference transfers 50 W in steady one-dimensional conduction. Contact resistances and edge losses are omitted."
        },
        "url": "https://lemonergy.com/learn/glossary/thermal-conductivity/",
        "mentions": [
          "heat-flux",
          "thermal-gradient"
        ]
      }
    },
    {
      "id": "term:cooling-plate",
      "type": "Term",
      "label": "Cooling plate",
      "properties": {
        "id": "cooling-plate",
        "name": "Cooling plate",
        "aka": [
          "cold plate"
        ],
        "section": "topic-thermal",
        "definition": "A flat aluminium channel assembly under or between the cells through which coolant, usually a water–glycol mix, is pumped. Heat crosses from cell to plate through a thermal interface material; the plate also sets the pack’s temperature uniformity.",
        "related": [
          "thermal-management",
          "thermal-interface-material",
          "immersion-cooling"
        ],
        "url": "https://lemonergy.com/learn/glossary/cooling-plate/",
        "mentions": [
          "thermal-gradient",
          "coolant"
        ]
      }
    },
    {
      "id": "term:passive-thermal-management",
      "type": "Term",
      "label": "Passive thermal management",
      "properties": {
        "id": "passive-thermal-management",
        "name": "Passive thermal management",
        "aka": [
          "passive cooling",
          "thermal insulation"
        ],
        "section": "topic-thermal",
        "definition": "Controlling battery temperature without pumps, fans or compressors. Heat leaves by conduction to the enclosure and natural convection, sometimes helped by fins or phase change material, while insulation slows heat gain in summer and keeps a parked pack warm in winter. It suits small, low-power packs such as phones and e-bikes, not fast-charging vehicles.",
        "related": [
          "phase-change-material",
          "heat-sink",
          "thermal-management",
          "enclosure",
          "thermal-mass"
        ],
        "url": "https://lemonergy.com/learn/glossary/passive-thermal-management/",
        "mentions": [
          "heat-transfer-modes"
        ]
      }
    }
  ]
}