{
  "node": {
    "id": "term:particle-size",
    "type": "Term",
    "label": "Particle size",
    "properties": {
      "id": "particle-size",
      "name": "Particle size",
      "aka": [
        "D50"
      ],
      "section": "topic-transport",
      "definition": "The diameter of active-material particles, usually quoted as D50, the median, in micrometres. Small particles shorten the solid diffusion path and favour power; large ones pack densely and favour energy and stability.",
      "unit": "µm",
      "related": [
        "solid-state-diffusion",
        "specific-surface-area",
        "rate-capability",
        "single-crystal"
      ],
      "url": "https://lemonergy.com/learn/glossary/particle-size/",
      "mentions": [
        "diffusion"
      ]
    }
  },
  "edges": [
    {
      "id": "edge:2107",
      "source": "term:particle-size",
      "target": "topic:topic-transport",
      "type": "belongsTo",
      "properties": {
        "sourceFile": "terms.json"
      }
    },
    {
      "id": "edge:2108",
      "source": "term:particle-size",
      "target": "term:solid-state-diffusion",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:2109",
      "source": "term:particle-size",
      "target": "term:specific-surface-area",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:2110",
      "source": "term:particle-size",
      "target": "term:rate-capability",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:2111",
      "source": "term:particle-size",
      "target": "term:single-crystal",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:mentions/particle-size/diffusion",
      "source": "term:particle-size",
      "target": "term:diffusion",
      "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-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"
      }
    },
    {
      "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:specific-surface-area",
      "type": "Term",
      "label": "Specific surface area",
      "properties": {
        "id": "specific-surface-area",
        "name": "Specific surface area",
        "abbr": "BET",
        "section": "topic-transport",
        "definition": "Surface per gram of a powder, measured by gas adsorption and quoted as the BET area in m²/g. More surface speeds the reaction but also grows more SEI, so graphite is engineered to a modest 1–3 m²/g.",
        "unit": "m²/g",
        "related": [
          "particle-size",
          "sei",
          "charge-transfer"
        ],
        "url": "https://lemonergy.com/learn/glossary/specific-surface-area/",
        "mentions": [
          "graphite"
        ]
      }
    },
    {
      "id": "term:rate-capability",
      "type": "Term",
      "label": "Rate capability",
      "properties": {
        "id": "rate-capability",
        "name": "Rate capability",
        "section": "topic-ratings",
        "definition": "How much of its capacity a cell can still deliver as the C-rate rises. It is measured by discharging at a series of rates and falls faster for thick, dense electrodes and at low temperature.",
        "related": [
          "c-rate",
          "ideal-duration",
          "polarization",
          "tortuosity",
          "peukert"
        ],
        "url": "https://lemonergy.com/learn/glossary/rate-capability/",
        "mentions": []
      }
    },
    {
      "id": "term:single-crystal",
      "type": "Term",
      "label": "Single-crystal cathode",
      "properties": {
        "id": "single-crystal",
        "name": "Single-crystal cathode",
        "section": "topic-chemistries",
        "definition": "Positive-electrode powder made of individual micron-sized crystals rather than agglomerates of many small grains. With no internal grain boundaries to crack open, it resists particle cracking and gassing and lasts longer at high voltage.",
        "related": [
          "particle-cracking",
          "high-nickel",
          "cathode-active-material"
        ],
        "url": "https://lemonergy.com/learn/glossary/single-crystal/",
        "mentions": [
          "gas-generation",
          "coating-defects"
        ]
      }
    },
    {
      "id": "term:diffusion",
      "type": "Term",
      "label": "Diffusion",
      "properties": {
        "id": "diffusion",
        "name": "Diffusion",
        "section": "topic-transport",
        "definition": "The net movement of a species from where it is concentrated to where it is scarce, driven by random thermal motion. In a cell lithium diffuses through the electrolyte in the pores and, far more slowly, through the solid particles themselves.",
        "related": [
          "ficks-first-law",
          "diffusion-coefficient",
          "solid-state-diffusion",
          "concentration-gradient",
          "migration"
        ],
        "lesson": "transport/ficks-first-law/#in-a-cell",
        "url": "https://lemonergy.com/learn/glossary/diffusion/",
        "mentions": [
          "electrolyte"
        ]
      }
    }
  ]
}