{
  "node": {
    "id": "term:voltage-fade",
    "type": "Term",
    "label": "Voltage fade",
    "properties": {
      "id": "voltage-fade",
      "name": "Voltage fade",
      "aka": [
        "voltage decay"
      ],
      "section": "topic-aging",
      "definition": "A gradual drop in a cell’s average discharge voltage as it cycles, distinct from capacity fade. It is a known weakness of the lithium-rich manganese cathode, whose structure migrates towards spinel-like phases, costing a few tenths of a volt over a few hundred cycles. Energy then falls even where ampere-hours hold, so it must be tracked in watt-hours.",
      "related": [
        "capacity-fade",
        "structural-degradation",
        "phase-transition",
        "nominal-energy",
        "state-of-energy"
      ],
      "url": "https://lemonergy.com/learn/glossary/voltage-fade/",
      "mentions": [
        "volt",
        "cathode",
        "lithium-rich-manganese",
        "manganese"
      ]
    }
  },
  "edges": [
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      "id": "edge:6571",
      "source": "term:voltage-fade",
      "target": "topic:topic-aging",
      "type": "belongsTo",
      "properties": {
        "sourceFile": "terms.json"
      }
    },
    {
      "id": "edge:6572",
      "source": "term:voltage-fade",
      "target": "term:capacity-fade",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:6573",
      "source": "term:voltage-fade",
      "target": "term:structural-degradation",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:6574",
      "source": "term:voltage-fade",
      "target": "term:phase-transition",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:6575",
      "source": "term:voltage-fade",
      "target": "term:nominal-energy",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:6576",
      "source": "term:voltage-fade",
      "target": "term:state-of-energy",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:mentions/voltage-fade/volt",
      "source": "term:voltage-fade",
      "target": "term:volt",
      "type": "mentions",
      "properties": {
        "sourceFile": "terms.json",
        "method": "build_glossary.mention_index + mentions",
        "field": "definition",
        "meaning": "Text mention; not a causal claim"
      }
    },
    {
      "id": "edge:mentions/voltage-fade/cathode",
      "source": "term:voltage-fade",
      "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/voltage-fade/lithium-rich-manganese",
      "source": "term:voltage-fade",
      "target": "term:lithium-rich-manganese",
      "type": "mentions",
      "properties": {
        "sourceFile": "terms.json",
        "method": "build_glossary.mention_index + mentions",
        "field": "definition",
        "meaning": "Text mention; not a causal claim"
      }
    },
    {
      "id": "edge:mentions/voltage-fade/manganese",
      "source": "term:voltage-fade",
      "target": "term:manganese",
      "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-aging",
      "type": "Topic",
      "label": "Aging and degradation",
      "properties": {
        "id": "topic-aging",
        "name": "Aging and degradation",
        "lede": "Why a cell loses capacity and gains resistance, and the mechanisms behind it.",
        "context": "Separate mechanisms, observations and fitted models.",
        "example": "Capacity loss and resistance rise can have different causes; a film-growth curve cannot identify both.",
        "lesson_url": "https://lemonergy.com/learn/fundamentals/battery-aging/",
        "lesson_label": "Open aging"
      }
    },
    {
      "id": "term:capacity-fade",
      "type": "Term",
      "label": "Capacity fade",
      "properties": {
        "id": "capacity-fade",
        "name": "Capacity fade",
        "section": "topic-aging",
        "definition": "The loss of charge a cell can store and deliver, for example through lithium locked into the SEI or active material that has cracked out of service.",
        "related": [
          "loss-of-lithium-inventory",
          "loss-of-active-material",
          "state-of-health",
          "knee-point"
        ],
        "lesson": "fundamentals/battery-aging/#chain",
        "url": "https://lemonergy.com/learn/glossary/capacity-fade/",
        "mentions": [
          "active-material",
          "sei"
        ]
      }
    },
    {
      "id": "term:structural-degradation",
      "type": "Term",
      "label": "Structural degradation",
      "properties": {
        "id": "structural-degradation",
        "name": "Structural degradation",
        "aka": [
          "phase transformation",
          "cation mixing"
        ],
        "section": "topic-aging",
        "definition": "Changes in the crystal structure of a positive material as it cycles: layered oxides can rearrange into spinel or rock-salt phases at the surface, with nickel ions migrating into lithium sites. The new phases block lithium transport and raise resistance.",
        "related": [
          "high-nickel",
          "phase-transition",
          "impedance-rise",
          "loss-of-active-material"
        ],
        "url": "https://lemonergy.com/learn/glossary/structural-degradation/",
        "mentions": [
          "lmo"
        ]
      }
    },
    {
      "id": "term:phase-transition",
      "type": "Term",
      "label": "Phase transition",
      "properties": {
        "id": "phase-transition",
        "name": "Phase transition",
        "aka": [
          "staging"
        ],
        "section": "topic-electrochemistry",
        "definition": "A change of crystal structure as lithium content varies, which fixes the potential while two phases coexist. Graphite fills in stages, LFP switches between two phases across almost its whole range, and these transitions make the peaks that aging diagnostics read.",
        "related": [
          "voltage-plateau",
          "differential-voltage-analysis",
          "lfp",
          "graphite",
          "structural-degradation"
        ],
        "url": "https://lemonergy.com/learn/glossary/phase-transition/",
        "mentions": []
      }
    },
    {
      "id": "term:nominal-energy",
      "type": "Term",
      "label": "Nominal energy",
      "properties": {
        "id": "nominal-energy",
        "name": "Nominal energy",
        "section": "topic-ratings",
        "definition": "Nominal capacity times nominal voltage, in watt-hours: the headline energy figure on a datasheet. The energy actually delivered depends on the load, the temperature and how the voltage curve is weighted.",
        "formula": "E = Q × V_nominal",
        "unit": "Wh",
        "related": [
          "nominal-capacity",
          "nominal-voltage",
          "watt-hour",
          "energy-density"
        ],
        "lesson": "fundamentals/capacity-and-c-rate/#energy",
        "example": {
          "title": "Turn capacity into a nominal energy",
          "text": "A 5 Ah cell with a nominal voltage of 3.6 V has 18 Wh of nominal energy. This estimate uses the nominal voltage; delivered energy is the integral of measured terminal voltage multiplied by current."
        },
        "url": "https://lemonergy.com/learn/glossary/nominal-energy/",
        "mentions": [
          "datasheet",
          "discharge-curve"
        ]
      }
    },
    {
      "id": "term:state-of-energy",
      "type": "Term",
      "label": "State of energy",
      "properties": {
        "id": "state-of-energy",
        "name": "State of energy",
        "abbr": "SOE",
        "section": "topic-state",
        "definition": "Remaining energy as a fraction of total energy, which differs from state of charge because the voltage falls as a cell empties. It is the quantity behind a range estimate, and is harder to estimate than SOC.",
        "unit": "%",
        "related": [
          "state-of-charge",
          "nominal-energy",
          "range"
        ],
        "url": "https://lemonergy.com/learn/glossary/state-of-energy/",
        "mentions": []
      }
    },
    {
      "id": "term:volt",
      "type": "Term",
      "label": "Volt",
      "properties": {
        "id": "volt",
        "name": "Volt",
        "abbr": "V",
        "section": "topic-units",
        "definition": "The SI unit of electric potential difference: one joule of energy per coulomb of charge. A lithium-ion cell sits around 3–4 V; packs reach hundreds of volts by putting cells in series.",
        "unit": "V",
        "related": [
          "voltage",
          "nominal-voltage",
          "series-parallel"
        ],
        "url": "https://lemonergy.com/learn/glossary/volt/",
        "mentions": [
          "coulomb",
          "joule"
        ]
      }
    },
    {
      "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:lithium-rich-manganese",
      "type": "Term",
      "label": "Lithium-rich manganese cathode",
      "properties": {
        "id": "lithium-rich-manganese",
        "name": "Lithium-rich manganese cathode",
        "abbr": "LMR",
        "aka": [
          "LRM",
          "lithium manganese-rich",
          "Li-rich layered oxide",
          "OLO",
          "LMR-NMC"
        ],
        "section": "topic-chemistries",
        "definition": "A layered oxide carrying extra lithium in the transition-metal layer, typically Li₁.₂Ni₀.₁₃Co₀.₁₃Mn₀.₅₄O₂. Above about 4.5 V on the first charge, oxygen joins the redox, giving more than 250 mAh/g with little nickel or cobalt. Voltage fade, oxygen loss and a large first-cycle loss slowed adoption; GM and LG Energy Solution plan LMR cells for 2028.",
        "related": [
          "layered-oxide",
          "nmc",
          "first-cycle-loss",
          "structural-degradation",
          "disordered-rock-salt",
          "high-nickel"
        ],
        "url": "https://lemonergy.com/learn/glossary/lithium-rich-manganese/",
        "mentions": [
          "milliampere-hour",
          "cobalt",
          "voltage-fade",
          "lattice-oxygen-release"
        ]
      }
    },
    {
      "id": "term:manganese",
      "type": "Term",
      "label": "Manganese",
      "properties": {
        "id": "manganese",
        "name": "Manganese",
        "aka": [
          "manganese sulfate",
          "high-purity manganese sulfate",
          "HPMSM"
        ],
        "section": "topic-sustainability",
        "definition": "A cheap, abundant metal used in NMC, LMO and LMFP positive electrodes and in alkaline cells. Ore comes mostly from South Africa, Gabon and Australia, but about 95 % of battery-grade high-purity manganese sulfate was refined in China in 2024, which puts manganese on critical-raw-material lists despite plentiful reserves.",
        "related": [
          "nmc",
          "lmo",
          "lmfp",
          "critical-raw-materials",
          "cobalt",
          "nickel-sulfate"
        ],
        "url": "https://lemonergy.com/learn/glossary/manganese/",
        "mentions": []
      }
    }
  ]
}