{
  "node": {
    "id": "term:single-particle-model",
    "type": "Term",
    "label": "Single-particle model",
    "properties": {
      "id": "single-particle-model",
      "name": "Single-particle model",
      "abbr": "SPM",
      "section": "topic-transport",
      "definition": "A simplified physics model that represents each electrode as one spherical particle and neglects electrolyte gradients. It runs fast enough for a BMS and is accurate at low to moderate currents.",
      "related": [
        "newman-model",
        "equivalent-circuit-model",
        "solid-state-diffusion",
        "bms"
      ],
      "url": "https://lemonergy.com/learn/glossary/single-particle-model/",
      "mentions": [
        "electrode",
        "electrolyte"
      ]
    }
  },
  "edges": [
    {
      "id": "edge:2136",
      "source": "term:single-particle-model",
      "target": "topic:topic-transport",
      "type": "belongsTo",
      "properties": {
        "sourceFile": "terms.json"
      }
    },
    {
      "id": "edge:2137",
      "source": "term:single-particle-model",
      "target": "term:newman-model",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:2138",
      "source": "term:single-particle-model",
      "target": "term:equivalent-circuit-model",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
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    },
    {
      "id": "edge:2139",
      "source": "term:single-particle-model",
      "target": "term:solid-state-diffusion",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:2140",
      "source": "term:single-particle-model",
      "target": "term:bms",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:mentions/single-particle-model/electrode",
      "source": "term:single-particle-model",
      "target": "term:electrode",
      "type": "mentions",
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      "id": "edge:mentions/single-particle-model/electrolyte",
      "source": "term:single-particle-model",
      "target": "term:electrolyte",
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        "sourceFile": "terms.json",
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        "field": "definition",
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    {
      "id": "topic:topic-transport",
      "type": "Topic",
      "label": "Transport and modelling",
      "properties": {
        "id": "topic-transport",
        "name": "Transport and modelling",
        "lede": "How ions move, and the equations and models that describe a cell.",
        "context": "Specify phase, direction and boundaries.",
        "example": "The same concentration difference across 10 μm gives ten times the gradient across 100 μm; at equal D, first-law flux magnitude is ten times greater.",
        "lesson_url": "https://lemonergy.com/learn/transport/ficks-first-law/",
        "lesson_label": "Open diffusion"
      }
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    {
      "id": "term:newman-model",
      "type": "Term",
      "label": "Newman model",
      "properties": {
        "id": "newman-model",
        "name": "Newman model",
        "abbr": "P2D",
        "aka": [
          "pseudo-two-dimensional model",
          "Doyle–Fuller–Newman",
          "DFN"
        ],
        "section": "topic-transport",
        "definition": "The standard physics-based lithium-ion cell model: porous-electrode theory across the cell thickness, with solid diffusion solved in a representative spherical particle at every point — hence pseudo-two-dimensional. It predicts voltage from first principles but needs dozens of parameters.",
        "related": [
          "porous-electrode-theory",
          "single-particle-model",
          "butler-volmer",
          "ficks-second-law",
          "parameterisation",
          "pybamm"
        ],
        "url": "https://lemonergy.com/learn/glossary/newman-model/",
        "mentions": [
          "diffusion"
        ]
      }
    },
    {
      "id": "term:equivalent-circuit-model",
      "type": "Term",
      "label": "Equivalent circuit model",
      "properties": {
        "id": "equivalent-circuit-model",
        "name": "Equivalent circuit model",
        "abbr": "ECM",
        "aka": [
          "Thevenin model"
        ],
        "section": "topic-transport",
        "definition": "A cell model built from a voltage source for OCV, a series resistor and one or more RC pairs for the slower dynamics. Its few parameters are fitted from pulse tests, and it is what most battery management systems run in real time.",
        "related": [
          "rc-pair",
          "open-circuit-voltage",
          "hppc",
          "kalman-filter",
          "single-particle-model"
        ],
        "url": "https://lemonergy.com/learn/glossary/equivalent-circuit-model/",
        "mentions": []
      }
    },
    {
      "id": "term:solid-state-diffusion",
      "type": "Term",
      "label": "Solid-state diffusion",
      "properties": {
        "id": "solid-state-diffusion",
        "name": "Solid-state diffusion",
        "section": "topic-transport",
        "definition": "Lithium moving through the crystal lattice of an active-material particle, with diffusion coefficients of about 10⁻¹⁶ to 10⁻¹³ m²/s — three or more orders of magnitude slower than the 10⁻¹⁰ m²/s of the liquid. It is usually the rate-limiting step for thick electrodes and large particles.",
        "unit": "m²/s",
        "related": [
          "diffusion-coefficient",
          "diffusion",
          "particle-size",
          "rate-capability",
          "gitt"
        ],
        "lesson": "transport/ficks-first-law/#in-a-cell",
        "url": "https://lemonergy.com/learn/glossary/solid-state-diffusion/",
        "mentions": []
      }
    },
    {
      "id": "term:bms",
      "type": "Term",
      "label": "Battery management system",
      "properties": {
        "id": "bms",
        "name": "Battery management system",
        "abbr": "BMS",
        "section": "topic-pack",
        "definition": "The electronics and software that keep a battery inside its safe window: measuring every cell voltage and many temperatures, estimating SOC and SOH, balancing cells, computing current limits, controlling the contactors and reporting over the vehicle network.",
        "related": [
          "state-of-charge",
          "cell-balancing",
          "state-of-power",
          "cell-supervision-circuit",
          "contactor",
          "can-bus"
        ],
        "lesson": "fundamentals/battery-basics/#cell-module-pack",
        "url": "https://lemonergy.com/learn/glossary/bms/",
        "mentions": [
          "state-of-health",
          "cell-voltage"
        ]
      }
    },
    {
      "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:electrolyte",
      "type": "Term",
      "label": "Electrolyte",
      "properties": {
        "id": "electrolyte",
        "name": "Electrolyte",
        "section": "topic-electrolytes",
        "definition": "The ion-conducting medium between the electrodes. In a liquid-electrolyte cell it fills the pores of both electrodes and the separator, so it is not a separate structural layer.",
        "related": [
          "lithium-salt",
          "carbonate-solvent",
          "electrolyte-additive",
          "ionic-conductivity",
          "solid-electrolyte",
          "ionic-liquid-electrolyte"
        ],
        "lesson": "fundamentals/cell-architecture/#electrolyte",
        "example": {
          "title": "Ions and electrons",
          "text": "Electrolyte carries ions between electrodes; the external circuit carries electrons. The two paths serve different roles."
        },
        "url": "https://lemonergy.com/learn/glossary/electrolyte/",
        "mentions": [
          "separator"
        ]
      }
    }
  ]
}