{
  "node": {
    "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"
      ]
    }
  },
  "edges": [
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      "source": "term:newman-model",
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      "source": "term:newman-model",
      "target": "term:porous-electrode-theory",
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        "meaning": "Related context; not a causal claim"
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      "id": "edge:2131",
      "source": "term:newman-model",
      "target": "term:ficks-second-law",
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      "id": "edge:2132",
      "source": "term:newman-model",
      "target": "term:parameterisation",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
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      "source": "term:newman-model",
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      "id": "edge:mentions/newman-model/diffusion",
      "source": "term:newman-model",
      "target": "term:diffusion",
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        "field": "definition",
        "meaning": "Text mention; not a causal claim"
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      "source": "term:newman-model",
      "target": "reference:doyle-model",
      "type": "cites",
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        "scope": "direct technical reference"
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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"
      }
    },
    {
      "id": "term:porous-electrode-theory",
      "type": "Term",
      "label": "Porous-electrode theory",
      "properties": {
        "id": "porous-electrode-theory",
        "name": "Porous-electrode theory",
        "section": "topic-transport",
        "definition": "The framework, due to Newman and co-workers, that treats a porous electrode as two overlapping continua — solid and electrolyte — exchanging current everywhere through their shared surface. It underlies every physics-based lithium-ion model.",
        "related": [
          "newman-model",
          "porous-electrode",
          "bruggeman-relation",
          "butler-volmer"
        ],
        "url": "https://lemonergy.com/learn/glossary/porous-electrode-theory/",
        "mentions": [
          "electrode",
          "electrolyte"
        ]
      }
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    {
      "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"
        ]
      }
    },
    {
      "id": "term:butler-volmer",
      "type": "Term",
      "label": "Butler–Volmer equation",
      "properties": {
        "id": "butler-volmer",
        "name": "Butler–Volmer equation",
        "section": "topic-electrochemistry",
        "definition": "The kinetic law relating current density at an electrode to its overpotential: current grows exponentially with overpotential in each direction. It is the charge-transfer term in every physics-based cell model.",
        "formula": "i = i₀[exp(α_a·Fη/RT) − exp(−α_c·Fη/RT)]",
        "related": [
          "overpotential",
          "exchange-current-density",
          "charge-transfer",
          "newman-model"
        ],
        "example": {
          "title": "Compare equilibrium with a positive overpotential",
          "text": "For a symmetric one-electron example at 298.15 K, αa = αc = 0.5 and η = 25.7 mV give i/i₀ ≈ 1.04. At η = 0 the forward and reverse contributions cancel, so net current is zero."
        },
        "url": "https://lemonergy.com/learn/glossary/butler-volmer/",
        "mentions": [
          "electrode"
        ]
      }
    },
    {
      "id": "term:ficks-second-law",
      "type": "Term",
      "label": "Fick’s second law",
      "properties": {
        "id": "ficks-second-law",
        "name": "Fick’s second law",
        "section": "topic-transport",
        "definition": "The time-dependent diffusion equation, ∂c/∂t = D ∂²c/∂x², obtained by combining Fick’s first law with conservation of mass. It is what a cell model solves inside each particle to follow lithium concentration over time.",
        "formula": "∂c/∂t = D · ∂²c/∂x²",
        "related": [
          "ficks-first-law",
          "solid-state-diffusion",
          "newman-model",
          "single-particle-model"
        ],
        "lesson": "transport/ficks-first-law/#assumptions",
        "example": {
          "title": "Compare diffusion time scales",
          "text": "For diffusion over an illustrative length of 10 μm with D = 10⁻¹⁴ m²/s, the scale L²/D is 10,000 s, about 2.8 h. Halving the length reduces this scale to one quarter; exact solutions also depend on geometry and boundaries."
        },
        "url": "https://lemonergy.com/learn/glossary/ficks-second-law/",
        "mentions": [
          "diffusion"
        ]
      }
    },
    {
      "id": "term:parameterisation",
      "type": "Term",
      "label": "Parameterisation",
      "properties": {
        "id": "parameterisation",
        "name": "Parameterisation",
        "aka": [
          "parameter identification"
        ],
        "section": "topic-transport",
        "definition": "Measuring or fitting the numbers a model needs: OCV curves, diffusion coefficients, exchange current densities, thicknesses and porosities for a physics model, or resistances and time constants for a circuit model. It is usually most of the modelling effort.",
        "related": [
          "newman-model",
          "equivalent-circuit-model",
          "gitt",
          "hppc",
          "electrochemical-impedance-spectroscopy"
        ],
        "url": "https://lemonergy.com/learn/glossary/parameterisation/",
        "mentions": [
          "open-circuit-voltage",
          "diffusion"
        ]
      }
    },
    {
      "id": "term:pybamm",
      "type": "Term",
      "label": "PyBaMM",
      "properties": {
        "id": "pybamm",
        "name": "PyBaMM",
        "section": "topic-transport",
        "definition": "An open-source Python package for battery modelling that implements the single-particle, Newman and several degradation models with interchangeable sub-models. It has become the common reference implementation in academic battery modelling.",
        "related": [
          "newman-model",
          "single-particle-model",
          "aging-model",
          "parameterisation"
        ],
        "url": "https://lemonergy.com/learn/glossary/pybamm/",
        "mentions": []
      }
    },
    {
      "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"
        ]
      }
    },
    {
      "id": "reference:doyle-model",
      "type": "Reference",
      "label": "Modeling of Galvanostatic Charge and Discharge of the Lithium/Polymer/Insertion Cell",
      "properties": {
        "title": "Modeling of Galvanostatic Charge and Discharge of the Lithium/Polymer/Insertion Cell",
        "publisher": "Journal of The Electrochemical Society",
        "url": "https://doi.org/10.1149/1.2221597",
        "type": "Research article",
        "scope": "Porous-electrode transport and insertion-cell modeling; foundational work rather than a specification for a particular commercial cell.",
        "year": 1993,
        "authors": [
          "Marc Doyle",
          "Thomas F. Fuller",
          "John Newman"
        ],
        "accessed": "2026-10-27"
      }
    }
  ]
}