{
  "node": {
    "id": "term:iron-air",
    "type": "Term",
    "label": "Iron–air battery",
    "properties": {
      "id": "iron-air",
      "name": "Iron–air battery",
      "aka": [
        "Fe–air battery",
        "rust battery"
      ],
      "section": "topic-other-chemistries",
      "definition": "A rechargeable alkaline cell that oxidises iron to iron hydroxide — reversible rusting — with oxygen drawn from the air, then reduces it back on charge. Iron is cheap enough that systems built for about 100 hours of discharge make sense for multi-day grid storage, though round-trip efficiency is low and hydrogen evolution on the iron wastes charge.",
      "related": [
        "long-duration-storage",
        "zinc-air",
        "nickel-iron",
        "stationary-storage",
        "levelized-cost-of-storage",
        "energy-efficiency"
      ],
      "url": "https://lemonergy.com/learn/glossary/iron-air/",
      "mentions": [
        "alkaline-cell"
      ]
    }
  },
  "edges": [
    {
      "id": "edge:5895",
      "source": "term:iron-air",
      "target": "topic:topic-other-chemistries",
      "type": "belongsTo",
      "properties": {
        "sourceFile": "terms.json"
      }
    },
    {
      "id": "edge:5896",
      "source": "term:iron-air",
      "target": "term:long-duration-storage",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:5897",
      "source": "term:iron-air",
      "target": "term:zinc-air",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:5898",
      "source": "term:iron-air",
      "target": "term:nickel-iron",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:5899",
      "source": "term:iron-air",
      "target": "term:stationary-storage",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:5900",
      "source": "term:iron-air",
      "target": "term:levelized-cost-of-storage",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:5901",
      "source": "term:iron-air",
      "target": "term:energy-efficiency",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:mentions/iron-air/alkaline-cell",
      "source": "term:iron-air",
      "target": "term:alkaline-cell",
      "type": "mentions",
      "properties": {
        "sourceFile": "terms.json",
        "method": "build_glossary.mention_index + mentions",
        "field": "definition",
        "meaning": "Text mention; not a causal claim"
      }
    }
  ],
  "neighbors": [
    {
      "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:long-duration-storage",
      "type": "Term",
      "label": "Long-duration energy storage",
      "properties": {
        "id": "long-duration-storage",
        "name": "Long-duration energy storage",
        "abbr": "LDES",
        "section": "topic-applications",
        "definition": "Storage that discharges for eight hours or more, filling gaps that lithium-ion’s one-to-four-hour systems leave. Flow, iron–air and thermal technologies compete for it by making energy capacity cheap even when power is not.",
        "related": [
          "stationary-storage",
          "flow-battery",
          "e-rate",
          "levelized-cost-of-storage"
        ],
        "url": "https://lemonergy.com/learn/glossary/long-duration-storage/",
        "mentions": []
      }
    },
    {
      "id": "term:zinc-air",
      "type": "Term",
      "label": "Zinc–air cell",
      "properties": {
        "id": "zinc-air",
        "name": "Zinc–air cell",
        "section": "topic-other-chemistries",
        "definition": "A cell whose positive electrode uses oxygen from the air, so almost all its volume is zinc and its energy density is very high. It powers hearing aids as a primary cell; rechargeable versions are being developed for grid storage.",
        "related": [
          "primary-cell",
          "alkaline-cell",
          "long-duration-storage"
        ],
        "url": "https://lemonergy.com/learn/glossary/zinc-air/",
        "mentions": [
          "electrode",
          "positive-electrode",
          "energy-density"
        ]
      }
    },
    {
      "id": "term:nickel-iron",
      "type": "Term",
      "label": "Nickel–iron battery",
      "properties": {
        "id": "nickel-iron",
        "name": "Nickel–iron battery",
        "abbr": "NiFe",
        "aka": [
          "Edison cell",
          "Edison battery"
        ],
        "section": "topic-other-chemistries",
        "definition": "A 1.2 V alkaline rechargeable cell with a nickel oxyhydroxide positive and iron negative, developed by Jungner and Edison around 1900. It is nearly indestructible, tolerating overcharge, deep discharge and decades of use, but low energy density, high self-discharge, hydrogen gassing and poor efficiency confined it to railways, mines and off-grid storage.",
        "related": [
          "nickel-cadmium",
          "nickel-metal-hydride",
          "iron-air",
          "self-discharge",
          "gas-generation"
        ],
        "url": "https://lemonergy.com/learn/glossary/nickel-iron/",
        "mentions": [
          "energy-density",
          "overcharge",
          "over-discharge"
        ]
      }
    },
    {
      "id": "term:stationary-storage",
      "type": "Term",
      "label": "Stationary storage",
      "properties": {
        "id": "stationary-storage",
        "name": "Stationary storage",
        "abbr": "BESS",
        "aka": [
          "battery energy storage system",
          "ESS"
        ],
        "section": "topic-applications",
        "definition": "Batteries installed in a fixed place — a container at a solar farm, a cabinet in a home — to shift energy in time or support the grid. LFP cells dominate because cost per cycle and safety matter more than mass.",
        "related": [
          "lfp",
          "energy-management-system",
          "inverter",
          "energy-arbitrage",
          "long-duration-storage",
          "ul-9540a"
        ],
        "url": "https://lemonergy.com/learn/glossary/stationary-storage/",
        "mentions": []
      }
    },
    {
      "id": "term:levelized-cost-of-storage",
      "type": "Term",
      "label": "Levelized cost of storage",
      "properties": {
        "id": "levelized-cost-of-storage",
        "name": "Levelized cost of storage",
        "abbr": "LCOS",
        "section": "topic-applications",
        "definition": "The total lifetime cost of a storage system divided by the total energy it will discharge, in currency per megawatt-hour. It folds cell price, efficiency, cycle life and degradation into one figure for comparing technologies.",
        "unit": "€/MWh",
        "related": [
          "cost-per-kwh",
          "cycle-life",
          "energy-efficiency",
          "stationary-storage"
        ],
        "url": "https://lemonergy.com/learn/glossary/levelized-cost-of-storage/",
        "mentions": []
      }
    },
    {
      "id": "term:energy-efficiency",
      "type": "Term",
      "label": "Energy efficiency",
      "properties": {
        "id": "energy-efficiency",
        "name": "Energy efficiency",
        "aka": [
          "round-trip efficiency"
        ],
        "section": "topic-ratings",
        "definition": "Energy out divided by energy in over a full cycle. It is lower than coulombic efficiency because the charge voltage sits above the discharge voltage; cells reach 95–98 %, and a full storage system 85–92 % after power electronics and cooling.",
        "unit": "%",
        "related": [
          "coulombic-efficiency",
          "voltage-hysteresis",
          "ir-drop",
          "stationary-storage",
          "voltage-efficiency"
        ],
        "url": "https://lemonergy.com/learn/glossary/energy-efficiency/",
        "mentions": []
      }
    },
    {
      "id": "term:alkaline-cell",
      "type": "Term",
      "label": "Alkaline cell",
      "properties": {
        "id": "alkaline-cell",
        "name": "Alkaline cell",
        "aka": [
          "zinc–manganese dioxide"
        ],
        "section": "topic-other-chemistries",
        "definition": "The common 1.5 V single-use cell, with a zinc negative electrode and manganese dioxide positive in potassium hydroxide electrolyte. It is the reference point for most people’s idea of a battery, and is not rechargeable.",
        "related": [
          "primary-cell",
          "zinc-air",
          "nominal-voltage",
          "zinc-carbon"
        ],
        "url": "https://lemonergy.com/learn/glossary/alkaline-cell/",
        "mentions": [
          "electrode",
          "negative-electrode",
          "electrolyte",
          "manganese"
        ]
      }
    }
  ]
}