{
  "node": {
    "id": "term:hybrid-energy-storage-system",
    "type": "Term",
    "label": "Hybrid energy storage system",
    "properties": {
      "id": "hybrid-energy-storage-system",
      "name": "Hybrid energy storage system",
      "abbr": "HESS",
      "section": "topic-applications",
      "definition": "Two storage technologies combined so each covers the part of the load it suits: typically a battery for energy, with supercapacitors, a flywheel or high-power cells for short peaks. In a bus or tram the supercapacitors absorb braking and acceleration pulses, sparing the battery the high currents that age it fastest.",
      "related": [
        "supercapacitor",
        "power-cell-energy-cell",
        "regenerative-braking",
        "ragone-plot",
        "lto"
      ],
      "url": "https://lemonergy.com/learn/glossary/hybrid-energy-storage-system/",
      "mentions": []
    }
  },
  "edges": [
    {
      "id": "edge:6816",
      "source": "term:hybrid-energy-storage-system",
      "target": "topic:topic-applications",
      "type": "belongsTo",
      "properties": {
        "sourceFile": "terms.json"
      }
    },
    {
      "id": "edge:6817",
      "source": "term:hybrid-energy-storage-system",
      "target": "term:supercapacitor",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:6818",
      "source": "term:hybrid-energy-storage-system",
      "target": "term:power-cell-energy-cell",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:6819",
      "source": "term:hybrid-energy-storage-system",
      "target": "term:regenerative-braking",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:6820",
      "source": "term:hybrid-energy-storage-system",
      "target": "term:ragone-plot",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:6821",
      "source": "term:hybrid-energy-storage-system",
      "target": "term:lto",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    }
  ],
  "neighbors": [
    {
      "id": "topic:topic-applications",
      "type": "Topic",
      "label": "Applications and market",
      "properties": {
        "id": "topic-applications",
        "name": "Applications and market",
        "lede": "Where batteries are used, and the terms used to buy, size and compare them.",
        "context": "Start with mission energy, peak power and operating conditions.",
        "example": "20 kWh total energy and a ten-second 100 kW peak constrain different design aspects.",
        "lesson_url": "https://lemonergy.com/learn/fundamentals/capacity-and-c-rate/",
        "lesson_label": "Open energy and power"
      }
    },
    {
      "id": "term:supercapacitor",
      "type": "Term",
      "label": "Supercapacitor",
      "properties": {
        "id": "supercapacitor",
        "name": "Supercapacitor",
        "aka": [
          "ultracapacitor",
          "EDLC"
        ],
        "section": "topic-electrochemistry",
        "definition": "A device that stores charge in the electric double layer on high-surface-area carbon rather than in a reaction. It delivers very high power and lasts a million cycles but stores only a few watt-hours per kilogram.",
        "related": [
          "double-layer",
          "specific-power",
          "ragone-plot",
          "hybrid-energy-storage-system"
        ],
        "url": "https://lemonergy.com/learn/glossary/supercapacitor/",
        "mentions": []
      }
    },
    {
      "id": "term:power-cell-energy-cell",
      "type": "Term",
      "label": "Power cell and energy cell",
      "properties": {
        "id": "power-cell-energy-cell",
        "name": "Power cell and energy cell",
        "section": "topic-applications",
        "definition": "Two design points of the same chemistry: a power cell has thin, porous electrodes and many tabs for high current and fast charging; an energy cell has thick, dense electrodes for maximum watt-hours. A hybrid car wants the first, a long-range car the second.",
        "related": [
          "specific-power",
          "specific-energy",
          "areal-loading",
          "cell-design"
        ],
        "url": "https://lemonergy.com/learn/glossary/power-cell-energy-cell/",
        "mentions": [
          "fast-charging"
        ]
      }
    },
    {
      "id": "term:regenerative-braking",
      "type": "Term",
      "label": "Regenerative braking",
      "properties": {
        "id": "regenerative-braking",
        "name": "Regenerative braking",
        "section": "topic-charging",
        "definition": "Using a vehicle’s motor as a generator while slowing down, so braking energy charges the battery in short high-current pulses. A cold or full battery cannot accept it, which is one reason a BMS computes charge power limits continuously.",
        "related": [
          "state-of-power",
          "fast-charging",
          "electric-vehicle",
          "load-profile"
        ],
        "url": "https://lemonergy.com/learn/glossary/regenerative-braking/",
        "mentions": [
          "bms"
        ]
      }
    },
    {
      "id": "term:ragone-plot",
      "type": "Term",
      "label": "Ragone plot",
      "properties": {
        "id": "ragone-plot",
        "name": "Ragone plot",
        "section": "topic-ratings",
        "definition": "A log–log chart of specific power against specific energy on which each storage technology occupies a region. Capacitors sit high and left, batteries lower and right, and a single cell traces a curve as it is discharged faster.",
        "related": [
          "specific-energy",
          "specific-power",
          "rate-capability"
        ],
        "url": "https://lemonergy.com/learn/glossary/ragone-plot/",
        "mentions": []
      }
    },
    {
      "id": "term:lto",
      "type": "Term",
      "label": "Lithium titanate",
      "properties": {
        "id": "lto",
        "name": "Lithium titanate",
        "abbr": "LTO",
        "section": "topic-components",
        "definition": "A negative active material, Li₄Ti₅O₁₂, that works at about 1.55 V above lithium, so it never plates lithium and forms almost no SEI. The price is a low cell voltage of about 2.4 V and low energy density, traded for very long life and fast charging.",
        "related": [
          "anode-active-material",
          "lithium-plating",
          "fast-charging",
          "cycle-life",
          "niobium-tungsten-oxide"
        ],
        "url": "https://lemonergy.com/learn/glossary/lto/",
        "mentions": [
          "active-material",
          "sei",
          "energy-density",
          "cell-voltage"
        ]
      }
    }
  ]
}