{
  "node": {
    "id": "term:fuel-cell",
    "type": "Term",
    "label": "Fuel cell",
    "properties": {
      "id": "fuel-cell",
      "name": "Fuel cell",
      "section": "topic-other-chemistries",
      "definition": "An electrochemical converter that makes electricity from a fuel, usually hydrogen, and oxygen as long as both are supplied, rather than storing energy in its electrodes. Fuel-cell vehicles still carry a battery to buffer power.",
      "related": [
        "flow-battery",
        "hybrid-vehicle",
        "redox-reaction"
      ],
      "url": "https://lemonergy.com/learn/glossary/fuel-cell/",
      "mentions": []
    }
  },
  "edges": [
    {
      "id": "edge:usedIn/term:fuel-cell/workflow:native-battery-fuel-cell-table",
      "source": "term:fuel-cell",
      "target": "workflow:native-battery-fuel-cell-table",
      "type": "usedIn",
      "properties": {
        "sourceFile": "wiki-blocks.json"
      }
    },
    {
      "id": "edge:usedIn/term:fuel-cell/workflow:native-battery-pem-stack",
      "source": "term:fuel-cell",
      "target": "workflow:native-battery-pem-stack",
      "type": "usedIn",
      "properties": {
        "sourceFile": "wiki-blocks.json"
      }
    },
    {
      "id": "edge:belongsTo/term:fuel-cell/topic:topic-other-chemistries",
      "source": "term:fuel-cell",
      "target": "topic:topic-other-chemistries",
      "type": "belongsTo",
      "properties": {
        "sourceFile": "terms.json"
      }
    },
    {
      "id": "edge:relatedTo/term:fuel-cell/term:flow-battery",
      "source": "term:fuel-cell",
      "target": "term:flow-battery",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:relatedTo/term:fuel-cell/term:hybrid-vehicle",
      "source": "term:fuel-cell",
      "target": "term:hybrid-vehicle",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:relatedTo/term:fuel-cell/term:redox-reaction",
      "source": "term:fuel-cell",
      "target": "term:redox-reaction",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    }
  ],
  "neighbors": [
    {
      "id": "workflow:native-battery-fuel-cell-table",
      "type": "Workflow",
      "label": "Tabulated fuel-cell stack worked example",
      "properties": {
        "id": "native-battery-fuel-cell-table",
        "title": "Tabulated fuel-cell stack worked example",
        "kind": "studio",
        "summary": "Interpolated polarization table with explicit out-of-table diagnostic.",
        "steps": [
          "Review the block inputs, units and model limits.",
          "Open the Studio example and run its bundled model.",
          "Compare the output channels with the numerical checks; change one input and run again."
        ],
        "example": "Use the defaults below with Stack current = 1.5 A. At 0 s, Stack voltage is 4.6 V. Additional checks are listed below.",
        "observe": "Inspect the outputs and numerical checks on the block reference page.",
        "limits": "This static table has no gas, thermal, pressure or electrochemical states. A measured polarization curve is required for a particular stack. The example verifies numerical behavior for synthetic parameters. Cell characterization and validation for an intended use are separate tasks.",
        "url": "https://design.lemonergy.com/cosim.html?example=block-battery-fuel-cell-table",
        "label": "Open Studio example",
        "evidence": [
          "docs/glossary/native-block-verification.json"
        ]
      }
    },
    {
      "id": "workflow:native-battery-pem-stack",
      "type": "Workflow",
      "label": "Reduced PEM fuel-cell stack worked example",
      "properties": {
        "id": "native-battery-pem-stack",
        "title": "Reduced PEM fuel-cell stack worked example",
        "kind": "studio",
        "summary": "Prescribed gas/temperature Nernst potential with activation, ohmic and limiting-current losses plus an identified polarization lag. No humidity, gas-flow or thermal network states.",
        "steps": [
          "Review the block inputs, units and model limits.",
          "Open the Studio example and run its bundled model.",
          "Compare the output channels with the numerical checks; change one input and run again."
        ],
        "example": "Use the defaults below with Stack current = 2 A, Cell temperature = 298.15 K, Hydrogen partial pressure = 100000 Pa, Oxygen partial pressure = 100000 Pa. At 0 s, Stack voltage is 6.038232542 V. Additional checks are listed below.",
        "observe": "Inspect the outputs and numerical checks on the block reference page.",
        "limits": "Positive gas pressures and temperature are required; current is nonnegative and below the limiting current. No hydration, gas-channel flow, internal thermal or conserving network states. Literature supplies background, not a claim to reproduce a full published model. The example verifies numerical behavior for synthetic parameters. Cell characterization and validation for an intended use are separate tasks.",
        "url": "https://design.lemonergy.com/cosim.html?example=block-battery-pem-stack",
        "label": "Open Studio example",
        "evidence": [
          "docs/glossary/native-block-verification.json"
        ]
      }
    },
    {
      "id": "topic:topic-other-chemistries",
      "type": "Topic",
      "label": "Other and emerging chemistries",
      "properties": {
        "id": "topic-other-chemistries",
        "name": "Other and emerging chemistries",
        "lede": "Batteries beyond today’s lithium-ion: lead, nickel and primary cells, flow and metal–air batteries, solid-state and lithium-metal cells, and the multivalent and sodium chemistries in development.",
        "context": "Do not carry lithium-ion assumptions into every chemistry.",
        "example": "Two chemistries can meet the same energy target with different voltage windows and charge termination.",
        "lesson_url": "https://lemonergy.com/learn/fundamentals/cell-anatomy/",
        "lesson_label": "Open cell anatomy"
      }
    },
    {
      "id": "term:flow-battery",
      "type": "Term",
      "label": "Flow battery",
      "properties": {
        "id": "flow-battery",
        "name": "Flow battery",
        "aka": [
          "vanadium redox flow battery",
          "VRFB"
        ],
        "section": "topic-other-chemistries",
        "definition": "A battery whose energy is stored in liquid electrolytes held in external tanks and pumped through a reaction stack. Energy and power scale independently, which suits long-duration grid storage; vanadium is the most developed chemistry.",
        "related": [
          "stationary-storage",
          "long-duration-storage",
          "redox-reaction",
          "fuel-cell"
        ],
        "url": "https://lemonergy.com/learn/glossary/flow-battery/",
        "mentions": []
      }
    },
    {
      "id": "term:hybrid-vehicle",
      "type": "Term",
      "label": "Hybrid and plug-in hybrid vehicle",
      "properties": {
        "id": "hybrid-vehicle",
        "name": "Hybrid and plug-in hybrid vehicle",
        "abbr": "HEV, PHEV",
        "section": "topic-applications",
        "definition": "A hybrid pairs an engine with a small battery, around 1 kWh, that is cycled hard for power rather than energy; a plug-in hybrid adds a 10–25 kWh pack that can be charged from the grid for electric-only driving. Their cells are designed for power and life rather than energy.",
        "related": [
          "electric-vehicle",
          "specific-power",
          "nickel-metal-hydride",
          "cycle-life",
          "48v-system"
        ],
        "url": "https://lemonergy.com/learn/glossary/hybrid-vehicle/",
        "mentions": [
          "kilowatt-hour"
        ]
      }
    },
    {
      "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": []
      }
    }
  ]
}