{
  "node": {
    "id": "term:potassium-ion",
    "type": "Term",
    "label": "Potassium-ion battery",
    "properties": {
      "id": "potassium-ion",
      "name": "Potassium-ion battery",
      "abbr": "K-ion",
      "aka": [
        "KIB"
      ],
      "section": "topic-other-chemistries",
      "definition": "A rocking-chair cell shuttling K⁺ ions. Unlike sodium, potassium intercalates into ordinary graphite, forming KC₈ at 279 mAh/g, and its low redox potential allows high cell voltage; potassium is also abundant. The large ion makes graphite swell by about 60 % and strains positives, so Prussian blue analogues with wide channels lead as cathodes.",
      "related": [
        "sodium-ion",
        "graphite",
        "prussian-blue-analogue",
        "rocking-chair",
        "intercalation"
      ],
      "url": "https://lemonergy.com/learn/glossary/potassium-ion/",
      "mentions": [
        "milliampere-hour",
        "cell-voltage"
      ]
    }
  },
  "edges": [
    {
      "id": "edge:5868",
      "source": "term:potassium-ion",
      "target": "topic:topic-other-chemistries",
      "type": "belongsTo",
      "properties": {
        "sourceFile": "terms.json"
      }
    },
    {
      "id": "edge:5869",
      "source": "term:potassium-ion",
      "target": "term:sodium-ion",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:5870",
      "source": "term:potassium-ion",
      "target": "term:graphite",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:5871",
      "source": "term:potassium-ion",
      "target": "term:prussian-blue-analogue",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:5872",
      "source": "term:potassium-ion",
      "target": "term:rocking-chair",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:5873",
      "source": "term:potassium-ion",
      "target": "term:intercalation",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:mentions/potassium-ion/milliampere-hour",
      "source": "term:potassium-ion",
      "target": "term:milliampere-hour",
      "type": "mentions",
      "properties": {
        "sourceFile": "terms.json",
        "method": "build_glossary.mention_index + mentions",
        "field": "definition",
        "meaning": "Text mention; not a causal claim"
      }
    },
    {
      "id": "edge:mentions/potassium-ion/cell-voltage",
      "source": "term:potassium-ion",
      "target": "term:cell-voltage",
      "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 electrode and a layered oxide or Prussian-blue positive. It uses no lithium, cobalt or copper, at the cost of lower energy density.",
        "related": [
          "hard-carbon",
          "lithium-ion",
          "energy-density",
          "stationary-storage",
          "seawater-battery"
        ],
        "url": "https://lemonergy.com/learn/glossary/sodium-ion/",
        "mentions": [
          "electrode",
          "negative-electrode",
          "cobalt",
          "layered-oxide"
        ]
      }
    },
    {
      "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"
        ]
      }
    },
    {
      "id": "term:prussian-blue-analogue",
      "type": "Term",
      "label": "Prussian blue analogue",
      "properties": {
        "id": "prussian-blue-analogue",
        "name": "Prussian blue analogue",
        "abbr": "PBA",
        "aka": [
          "Prussian white",
          "hexacyanoferrate"
        ],
        "section": "topic-other-chemistries",
        "definition": "An open-framework compound, AₓM[Fe(CN)₆], in which iron–cyanide units and another metal form a cubic cage with wide channels for large ions. Made at low temperature from cheap elements, its sodium-rich form, Prussian white, is a leading sodium-ion cathode. Water trapped in the lattice degrades cells, and the cyanide groups raise questions in thermal runaway.",
        "related": [
          "sodium-ion",
          "potassium-ion",
          "cathode-active-material",
          "moisture-content",
          "ammonium-ion"
        ],
        "url": "https://lemonergy.com/learn/glossary/prussian-blue-analogue/",
        "mentions": [
          "cathode",
          "thermal-runaway"
        ]
      }
    },
    {
      "id": "term:rocking-chair",
      "type": "Term",
      "label": "Rocking-chair mechanism",
      "properties": {
        "id": "rocking-chair",
        "name": "Rocking-chair mechanism",
        "section": "topic-chemistries",
        "definition": "The working principle of a lithium-ion cell: lithium ions rock back and forth between host electrodes and are neither plated nor dissolved. Because the electrodes are only hosts, the ion count stays fixed and the cell can cycle thousands of times.",
        "related": [
          "lithium-ion",
          "intercalation",
          "lithium-metal-battery"
        ],
        "url": "https://lemonergy.com/learn/glossary/rocking-chair/",
        "mentions": []
      }
    },
    {
      "id": "term:intercalation",
      "type": "Term",
      "label": "Intercalation",
      "properties": {
        "id": "intercalation",
        "name": "Intercalation",
        "section": "topic-electrochemistry",
        "definition": "Lithium inserting into, and leaving, the host structure of an electrode material — between graphite layers, for example — without destroying it.",
        "related": [
          "graphite",
          "rocking-chair",
          "lithium-plating",
          "conversion-reaction",
          "alloying"
        ],
        "lesson": "fundamentals/battery-aging/#plating",
        "url": "https://lemonergy.com/learn/glossary/intercalation/",
        "mentions": [
          "electrode"
        ]
      }
    },
    {
      "id": "term:milliampere-hour",
      "type": "Term",
      "label": "Milliampere-hour",
      "properties": {
        "id": "milliampere-hour",
        "name": "Milliampere-hour",
        "abbr": "mAh",
        "section": "topic-units",
        "definition": "One thousandth of an ampere-hour, the capacity unit used for small cells. A phone cell of 4500 mAh holds 4.5 Ah; multiplied by its nominal voltage that is about 17 Wh.",
        "unit": "mAh",
        "related": [
          "ampere-hour",
          "watt-hour"
        ],
        "url": "https://lemonergy.com/learn/glossary/milliampere-hour/",
        "mentions": [
          "nominal-voltage"
        ]
      }
    },
    {
      "id": "term:cell-voltage",
      "type": "Term",
      "label": "Cell voltage",
      "properties": {
        "id": "cell-voltage",
        "name": "Cell voltage",
        "aka": [
          "electromotive force",
          "EMF"
        ],
        "section": "topic-electrochemistry",
        "definition": "The difference between the positive and negative electrode potentials at equilibrium: for NMC against graphite about 3.7 V. It is set by the chemistry, and the difference in Gibbs free energy of the cell reaction per unit charge.",
        "formula": "E = E₊ − E₋ = −ΔG / nF",
        "unit": "V",
        "related": [
          "electrode-potential",
          "gibbs-free-energy",
          "open-circuit-voltage",
          "nominal-voltage"
        ],
        "example": {
          "title": "Subtract equilibrium electrode potentials",
          "text": "If two illustrative electrode potentials are 4.0 V and 0.2 V versus the same reference, their equilibrium cell voltage is 3.8 V. Under load, resistance and polarization change the measured terminal voltage."
        },
        "url": "https://lemonergy.com/learn/glossary/cell-voltage/",
        "mentions": [
          "electrode",
          "negative-electrode",
          "graphite"
        ]
      }
    }
  ]
}