{
  "node": {
    "id": "term:anode-overhang",
    "type": "Term",
    "label": "Anode overhang",
    "properties": {
      "id": "anode-overhang",
      "name": "Anode overhang",
      "aka": [
        "negative electrode overhang",
        "overhang effect"
      ],
      "section": "topic-components",
      "definition": "The margin, of the order of a millimetre, by which the negative electrode extends beyond the positive electrode at every edge, so lithium leaving the cathode edge always finds graphite to enter rather than plating. The overhang slowly soaks up and gives back lithium itself, which causes small apparent capacity drifts in storage and efficiency tests.",
      "related": [
        "np-ratio",
        "lithium-plating",
        "cell-design",
        "coulombic-efficiency",
        "calendar-aging"
      ],
      "url": "https://lemonergy.com/learn/glossary/anode-overhang/",
      "mentions": [
        "electrode",
        "negative-electrode",
        "positive-electrode",
        "cathode",
        "graphite"
      ]
    }
  },
  "edges": [
    {
      "id": "edge:5685",
      "source": "term:anode-overhang",
      "target": "topic:topic-components",
      "type": "belongsTo",
      "properties": {
        "sourceFile": "terms.json"
      }
    },
    {
      "id": "edge:5686",
      "source": "term:anode-overhang",
      "target": "term:np-ratio",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:5687",
      "source": "term:anode-overhang",
      "target": "term:lithium-plating",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:5688",
      "source": "term:anode-overhang",
      "target": "term:cell-design",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:5689",
      "source": "term:anode-overhang",
      "target": "term:coulombic-efficiency",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:5690",
      "source": "term:anode-overhang",
      "target": "term:calendar-aging",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:mentions/anode-overhang/electrode",
      "source": "term:anode-overhang",
      "target": "term:electrode",
      "type": "mentions",
      "properties": {
        "sourceFile": "terms.json",
        "method": "build_glossary.mention_index + mentions",
        "field": "definition",
        "meaning": "Text mention; not a causal claim"
      }
    },
    {
      "id": "edge:mentions/anode-overhang/negative-electrode",
      "source": "term:anode-overhang",
      "target": "term:negative-electrode",
      "type": "mentions",
      "properties": {
        "sourceFile": "terms.json",
        "method": "build_glossary.mention_index + mentions",
        "field": "definition",
        "meaning": "Text mention; not a causal claim"
      }
    },
    {
      "id": "edge:mentions/anode-overhang/positive-electrode",
      "source": "term:anode-overhang",
      "target": "term:positive-electrode",
      "type": "mentions",
      "properties": {
        "sourceFile": "terms.json",
        "method": "build_glossary.mention_index + mentions",
        "field": "definition",
        "meaning": "Text mention; not a causal claim"
      }
    },
    {
      "id": "edge:mentions/anode-overhang/cathode",
      "source": "term:anode-overhang",
      "target": "term:cathode",
      "type": "mentions",
      "properties": {
        "sourceFile": "terms.json",
        "method": "build_glossary.mention_index + mentions",
        "field": "definition",
        "meaning": "Text mention; not a causal claim"
      }
    },
    {
      "id": "edge:mentions/anode-overhang/graphite",
      "source": "term:anode-overhang",
      "target": "term:graphite",
      "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-components",
      "type": "Topic",
      "label": "Cell components and electrode materials",
      "properties": {
        "id": "topic-components",
        "name": "Cell components and electrode materials",
        "lede": "What a cell is physically made of — active materials, binders, additives, foils and tabs — and how its electrodes are put together.",
        "context": "Connect each material with its function.",
        "example": "Electrons travel through additive, foil and tab; ions use electrolyte and separator pathways.",
        "lesson_url": "https://lemonergy.com/learn/fundamentals/cell-anatomy/",
        "lesson_label": "Open cell anatomy"
      }
    },
    {
      "id": "term:np-ratio",
      "type": "Term",
      "label": "N/P ratio",
      "properties": {
        "id": "np-ratio",
        "name": "N/P ratio",
        "section": "topic-components",
        "definition": "The areal capacity of the negative electrode divided by that of the positive electrode facing it, usually set at 1.05–1.15. The excess negative capacity ensures there is always a graphite site for every lithium ion on charge, which guards against lithium plating.",
        "formula": "N/P = Q_neg / Q_pos",
        "related": [
          "areal-loading",
          "lithium-plating",
          "cell-design",
          "overhang-alignment",
          "anode-overhang"
        ],
        "example": {
          "title": "Compare electrode capacity budgets",
          "text": "A negative-electrode capacity of 3.3 mAh/cm² paired with a positive-electrode capacity of 3.0 mAh/cm² gives an N/P ratio of 1.10. The chosen capacity definitions and operating windows must match."
        },
        "url": "https://lemonergy.com/learn/glossary/np-ratio/",
        "mentions": [
          "electrode",
          "negative-electrode",
          "positive-electrode",
          "graphite"
        ]
      }
    },
    {
      "id": "term:lithium-plating",
      "type": "Term",
      "label": "Lithium plating",
      "properties": {
        "id": "lithium-plating",
        "name": "Lithium plating",
        "section": "topic-aging",
        "definition": "Lithium metal depositing on the negative-electrode surface instead of intercalating into it. It is promoted by charging at low temperature or high current.",
        "related": [
          "dendrite",
          "fast-charging",
          "intercalation",
          "np-ratio",
          "dead-lithium",
          "electrodeposition"
        ],
        "lesson": "fundamentals/battery-aging/#plating",
        "url": "https://lemonergy.com/learn/glossary/lithium-plating/",
        "mentions": []
      }
    },
    {
      "id": "term:cell-design",
      "type": "Term",
      "label": "Cell design",
      "properties": {
        "id": "cell-design",
        "name": "Cell design",
        "section": "topic-manufacturing",
        "definition": "Choosing the chemistry, electrode loadings, porosities, N/P ratio, separator, electrolyte volume and format that together meet an energy, power, life, safety and cost target. Each choice trades against the others: thicker electrodes raise energy and lower power.",
        "related": [
          "np-ratio",
          "areal-loading",
          "porosity",
          "energy-density",
          "specific-power"
        ],
        "url": "https://lemonergy.com/learn/glossary/cell-design/",
        "mentions": [
          "electrode",
          "separator",
          "electrolyte"
        ]
      }
    },
    {
      "id": "term:coulombic-efficiency",
      "type": "Term",
      "label": "Coulombic efficiency",
      "properties": {
        "id": "coulombic-efficiency",
        "name": "Coulombic efficiency",
        "abbr": "CE",
        "section": "topic-ratings",
        "definition": "Charge delivered on discharge divided by charge put in on the previous charge. A healthy lithium-ion cell exceeds 99.9 %; the missing fraction is lithium lost to side reactions, so CE is an early and sensitive aging signal.",
        "formula": "CE = Q_discharge / Q_charge",
        "unit": "%",
        "related": [
          "energy-efficiency",
          "loss-of-lithium-inventory",
          "sei",
          "formation"
        ],
        "example": {
          "title": "Compare charge in and charge out",
          "text": "If a defined test charges 5.00 Ah and subsequently discharges 4.95 Ah over the chosen voltage window, its coulombic efficiency is 99%. This ratio alone does not include voltage-related energy loss."
        },
        "url": "https://lemonergy.com/learn/glossary/coulombic-efficiency/",
        "mentions": []
      }
    },
    {
      "id": "term:calendar-aging",
      "type": "Term",
      "label": "Calendar aging",
      "properties": {
        "id": "calendar-aging",
        "name": "Calendar aging",
        "section": "topic-aging",
        "definition": "Degradation that happens with time even when a cell is not cycled — in storage, for example. It is driven mainly by side reactions such as SEI growth and accelerates with temperature.",
        "related": [
          "cycle-aging",
          "sei",
          "arrhenius",
          "square-root-of-time",
          "calendar-life"
        ],
        "lesson": "fundamentals/battery-aging/#whole-cell",
        "url": "https://lemonergy.com/learn/glossary/calendar-aging/",
        "mentions": []
      }
    },
    {
      "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:negative-electrode",
      "type": "Term",
      "label": "Negative electrode",
      "properties": {
        "id": "negative-electrode",
        "name": "Negative electrode",
        "section": "topic-components",
        "definition": "The electrode at the lower potential, usually graphite on copper foil in a lithium-ion cell. It holds the lithium when the cell is charged and releases it on discharge, and industry calls it the anode.",
        "related": [
          "anode",
          "graphite",
          "positive-electrode",
          "copper-foil"
        ],
        "lesson": "fundamentals/cell-anatomy/#anode-cathode",
        "example": {
          "title": "Keep the polarity name",
          "text": "Graphite remains the negative electrode during charge and discharge, while the anode/cathode reaction labels change with operating direction."
        },
        "url": "https://lemonergy.com/learn/glossary/negative-electrode/",
        "mentions": [
          "electrode"
        ]
      }
    },
    {
      "id": "term:positive-electrode",
      "type": "Term",
      "label": "Positive electrode",
      "properties": {
        "id": "positive-electrode",
        "name": "Positive electrode",
        "section": "topic-components",
        "definition": "The electrode at the higher potential: a lithium metal oxide or phosphate coated on aluminium foil. It is the lithium source when a cell is built, and industry calls it the cathode.",
        "related": [
          "cathode",
          "cathode-active-material",
          "negative-electrode",
          "aluminium-foil"
        ],
        "lesson": "fundamentals/cell-anatomy/#anode-cathode",
        "example": {
          "title": "Polarity and reaction",
          "text": "The positive electrode retains its polarity label while its electrochemical reaction reverses between charge and discharge."
        },
        "url": "https://lemonergy.com/learn/glossary/positive-electrode/",
        "mentions": [
          "electrode"
        ]
      }
    },
    {
      "id": "term:cathode",
      "type": "Term",
      "label": "Cathode",
      "properties": {
        "id": "cathode",
        "name": "Cathode",
        "section": "topic-components",
        "definition": "The electrode where reduction happens: the positive electrode on discharge, the negative one on charge. In industry usage, “cathode” means the positive electrode and its material, whatever the cell is doing.",
        "related": [
          "positive-electrode",
          "anode",
          "reduction",
          "cathode-active-material"
        ],
        "lesson": "fundamentals/cell-anatomy/#anode-cathode",
        "example": {
          "title": "Check the reaction",
          "text": "During discharge, the positive electrode is the cathode because reduction occurs there. Charging moves reduction to the negative electrode."
        },
        "url": "https://lemonergy.com/learn/glossary/cathode/",
        "mentions": [
          "electrode"
        ]
      }
    },
    {
      "id": "term:graphite",
      "type": "Term",
      "label": "Graphite",
      "properties": {
        "id": "graphite",
        "name": "Graphite",
        "section": "topic-components",
        "definition": "Layered carbon, the negative active material of nearly all lithium-ion cells. Lithium intercalates between its layers up to LiC₆, a theoretical 372 mAh/g, at a potential about 0.1 V above lithium metal.",
        "related": [
          "anode-active-material",
          "intercalation",
          "natural-graphite",
          "synthetic-graphite",
          "lithium-plating"
        ],
        "lesson": "fundamentals/cell-anatomy/#components",
        "example": {
          "title": "Compare matching mass bases",
          "text": "A graphite value per gram of active material cannot be directly compared with a value including binder, additive and foil."
        },
        "url": "https://lemonergy.com/learn/glossary/graphite/",
        "mentions": [
          "milliampere-hour",
          "active-material"
        ]
      }
    }
  ]
}