{
  "node": {
    "id": "term:nfm",
    "type": "Term",
    "label": "Sodium nickel-iron-manganese oxide",
    "properties": {
      "id": "nfm",
      "name": "Sodium nickel-iron-manganese oxide",
      "abbr": "NFM",
      "aka": [
        "NaNi⅓Fe⅓Mn⅓O₂",
        "sodium layered oxide"
      ],
      "section": "topic-other-chemistries",
      "definition": "A layered-oxide sodium-ion positive electrode containing nickel, iron and manganese, usually in the O3 structure. It gives the most energy of the common sodium-ion cathodes, with cells around 3.0–3.1 V nominal, but it is sensitive to moisture and typically lasts fewer cycles than polyanionic NFPP.",
      "related": [
        "sodium-ion",
        "layered-oxide",
        "nfpp",
        "hard-carbon",
        "energy-density"
      ],
      "url": "https://lemonergy.com/learn/glossary/nfm/",
      "mentions": [
        "electrode",
        "positive-electrode",
        "polyanionic-cathode",
        "manganese"
      ]
    }
  },
  "edges": [
    {
      "id": "edge:belongsTo/term:nfm/topic:topic-other-chemistries",
      "source": "term:nfm",
      "target": "topic:topic-other-chemistries",
      "type": "belongsTo",
      "properties": {
        "sourceFile": "terms.json"
      }
    },
    {
      "id": "edge:relatedTo/term:nfm/term:sodium-ion",
      "source": "term:nfm",
      "target": "term:sodium-ion",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:relatedTo/term:nfm/term:layered-oxide",
      "source": "term:nfm",
      "target": "term:layered-oxide",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:relatedTo/term:nfm/term:nfpp",
      "source": "term:nfm",
      "target": "term:nfpp",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:relatedTo/term:nfm/term:hard-carbon",
      "source": "term:nfm",
      "target": "term:hard-carbon",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:relatedTo/term:nfm/term:energy-density",
      "source": "term:nfm",
      "target": "term:energy-density",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:mentions/nfm/electrode",
      "source": "term:nfm",
      "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/nfm/positive-electrode",
      "source": "term:nfm",
      "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/nfm/polyanionic-cathode",
      "source": "term:nfm",
      "target": "term:polyanionic-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/nfm/manganese",
      "source": "term:nfm",
      "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-other-chemistries",
      "type": "Topic",
      "label": "Other and emerging chemistries",
      "properties": {
        "id": "topic-other-chemistries",
        "name": "Other and emerging chemistries",
        "lede": "Batteries beyond today’s lithium-ion: lead, nickel and primary cells, flow and metal–air batteries, solid-state and lithium-metal cells, and the multivalent and sodium chemistries in development.",
        "context": "Do not carry lithium-ion assumptions into every chemistry.",
        "example": "Two chemistries can meet the same energy target with different voltage windows and charge termination.",
        "lesson_url": "https://lemonergy.com/learn/fundamentals/cell-anatomy/",
        "lesson_label": "Open cell anatomy"
      }
    },
    {
      "id": "term:sodium-ion",
      "type": "Term",
      "label": "Sodium-ion battery",
      "properties": {
        "id": "sodium-ion",
        "name": "Sodium-ion battery",
        "abbr": "Na-ion",
        "section": "topic-other-chemistries",
        "definition": "A cell built like a lithium-ion cell but shuttling sodium ions, usually between a hard-carbon negative and a layered-oxide (NFM), polyanionic (NFPP, NVP) or Prussian-blue positive. It uses no lithium or cobalt and needs no copper foil, so it can be stored at 0 V, at the cost of lower energy density.",
        "related": [
          "hard-carbon",
          "nfpp",
          "lithium-ion",
          "energy-density",
          "stationary-storage",
          "seawater-battery"
        ],
        "aka": [
          "SIB",
          "Na-ion battery",
          "sodium-ion cell"
        ],
        "url": "https://lemonergy.com/learn/glossary/sodium-ion/",
        "mentions": [
          "copper-foil",
          "nfm",
          "nvp",
          "cobalt",
          "polyanionic-cathode"
        ]
      }
    },
    {
      "id": "term:layered-oxide",
      "type": "Term",
      "label": "Layered oxide",
      "properties": {
        "id": "layered-oxide",
        "name": "Layered oxide",
        "abbr": "LTMO",
        "aka": [
          "layered transition-metal oxide",
          "α-NaFeO₂ structure",
          "O3 structure",
          "P2 structure"
        ],
        "section": "topic-chemistries",
        "definition": "The crystal structure of LCO, NMC and NCA: close-packed oxygen layers with lithium and transition-metal ions in alternate layers of octahedral sites, so lithium moves in two-dimensional sheets. The structure offers high capacity and voltage but can distort or mix cations when deeply delithiated. Sodium versions are labelled O3 or P2 by their stacking.",
        "related": [
          "nmc",
          "lco",
          "nca",
          "structural-degradation",
          "spinel-structure",
          "sodium-ion"
        ],
        "url": "https://lemonergy.com/learn/glossary/layered-oxide/",
        "mentions": [
          "stacking"
        ]
      }
    },
    {
      "id": "term:nfpp",
      "type": "Term",
      "label": "Sodium iron pyrophosphate-phosphate",
      "properties": {
        "id": "nfpp",
        "name": "Sodium iron pyrophosphate-phosphate",
        "abbr": "NFPP",
        "aka": [
          "Na₄Fe₃(PO₄)₂P₂O₇",
          "sodium iron phosphate-pyrophosphate"
        ],
        "section": "topic-other-chemistries",
        "definition": "A polyanionic sodium-ion positive electrode, Na₄Fe₃(PO₄)₂P₂O₇, made from cheap iron and phosphate. With a hard-carbon negative it gives cells of about 2.8–3.0 V nominal with long cycle life and good thermal stability, but less energy than layered oxides. It plays the role LFP plays among lithium-ion chemistries.",
        "related": [
          "sodium-ion",
          "polyanionic-cathode",
          "hard-carbon",
          "lfp",
          "nvp",
          "nfm"
        ],
        "url": "https://lemonergy.com/learn/glossary/nfpp/",
        "mentions": [
          "electrode",
          "positive-electrode",
          "cycle-life"
        ]
      }
    },
    {
      "id": "term:hard-carbon",
      "type": "Term",
      "label": "Hard carbon",
      "properties": {
        "id": "hard-carbon",
        "name": "Hard carbon",
        "section": "topic-components",
        "definition": "A disordered, non-graphitisable carbon used as the negative electrode of sodium-ion cells, where graphite barely works, and as a fast-charge additive in lithium-ion. Its open structure accepts ions without the strict layer spacing of graphite.",
        "related": [
          "sodium-ion",
          "graphite",
          "anode-active-material"
        ],
        "url": "https://lemonergy.com/learn/glossary/hard-carbon/",
        "mentions": [
          "electrode",
          "negative-electrode"
        ]
      }
    },
    {
      "id": "term:energy-density",
      "type": "Term",
      "label": "Energy density",
      "properties": {
        "id": "energy-density",
        "name": "Energy density",
        "aka": [
          "volumetric energy density"
        ],
        "section": "topic-ratings",
        "definition": "Stored energy per unit volume, in watt-hours per litre. It is the figure that matters when space is the constraint, as in a phone or under a car floor; high-energy cylindrical cells pass 700 Wh/L.",
        "unit": "Wh/L",
        "related": [
          "specific-energy",
          "nominal-energy",
          "ragone-plot",
          "areal-loading"
        ],
        "lesson": "fundamentals/capacity-and-c-rate/#energy",
        "url": "https://lemonergy.com/learn/glossary/energy-density/",
        "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: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:polyanionic-cathode",
      "type": "Term",
      "label": "Polyanionic cathode",
      "properties": {
        "id": "polyanionic-cathode",
        "name": "Polyanionic cathode",
        "aka": [
          "polyanion cathode",
          "NVPF",
          "NFPP",
          "phosphate cathode"
        ],
        "section": "topic-other-chemistries",
        "definition": "A positive material built from transition metals and polyanion groups such as PO₄³⁻, SO₄²⁻ or P₂O₇⁴⁻. The strongly bonded groups raise the voltage through the inductive effect and hold oxygen tightly, giving long life and safety at some cost in capacity and conductivity. LFP is the lithium example; Na₃V₂(PO₄)₂F₃ and iron-based Na₄Fe₃(PO₄)₂P₂O₇ serve sodium-ion cells.",
        "related": [
          "lfp",
          "olivine-structure",
          "sodium-ion",
          "prussian-blue-analogue",
          "layered-oxide"
        ],
        "url": "https://lemonergy.com/learn/glossary/polyanionic-cathode/",
        "mentions": [
          "nfpp"
        ]
      }
    },
    {
      "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": []
      }
    }
  ]
}