{
  "node": {
    "id": "term:lithium-sulfur",
    "type": "Term",
    "label": "Lithium–sulfur battery",
    "properties": {
      "id": "lithium-sulfur",
      "name": "Lithium–sulfur battery",
      "abbr": "Li–S",
      "section": "topic-other-chemistries",
      "definition": "A cell pairing a lithium-metal negative electrode with a sulfur positive electrode, which is cheap, light and converts rather than intercalates. Theoretical specific energy is very high; dissolving polysulfides and short cycle life are the obstacles.",
      "related": [
        "conversion-reaction",
        "lithium-metal-battery",
        "specific-energy",
        "polysulfide-shuttle"
      ],
      "url": "https://lemonergy.com/learn/glossary/lithium-sulfur/",
      "mentions": [
        "electrode",
        "negative-electrode",
        "positive-electrode",
        "cycle-life"
      ]
    }
  },
  "edges": [
    {
      "id": "edge:771",
      "source": "term:lithium-sulfur",
      "target": "topic:topic-other-chemistries",
      "type": "belongsTo",
      "properties": {
        "sourceFile": "terms.json"
      }
    },
    {
      "id": "edge:772",
      "source": "term:lithium-sulfur",
      "target": "term:conversion-reaction",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:773",
      "source": "term:lithium-sulfur",
      "target": "term:lithium-metal-battery",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:774",
      "source": "term:lithium-sulfur",
      "target": "term:specific-energy",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:775",
      "source": "term:lithium-sulfur",
      "target": "term:polysulfide-shuttle",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:mentions/lithium-sulfur/electrode",
      "source": "term:lithium-sulfur",
      "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/lithium-sulfur/negative-electrode",
      "source": "term:lithium-sulfur",
      "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/lithium-sulfur/positive-electrode",
      "source": "term:lithium-sulfur",
      "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/lithium-sulfur/cycle-life",
      "source": "term:lithium-sulfur",
      "target": "term:cycle-life",
      "type": "mentions",
      "properties": {
        "sourceFile": "terms.json",
        "method": "build_glossary.mention_index + mentions",
        "field": "definition",
        "meaning": "Text mention; not a causal claim"
      }
    },
    {
      "id": "edge:780",
      "source": "term:lithium-sulfur",
      "target": "reference:choi-post-li",
      "type": "cites",
      "properties": {
        "sourceFile": "wiki-references.json",
        "scope": "direct technical reference"
      }
    }
  ],
  "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:conversion-reaction",
      "type": "Term",
      "label": "Conversion reaction",
      "properties": {
        "id": "conversion-reaction",
        "name": "Conversion reaction",
        "section": "topic-electrochemistry",
        "definition": "An electrode reaction in which the host compound is broken down and reformed, as sulfur or a metal fluoride is, rather than lithium slotting into an intact structure. Conversion materials store more charge than intercalation hosts but suffer large volume change and voltage hysteresis.",
        "related": [
          "intercalation",
          "alloying",
          "lithium-sulfur",
          "voltage-hysteresis"
        ],
        "url": "https://lemonergy.com/learn/glossary/conversion-reaction/",
        "mentions": [
          "electrode"
        ]
      }
    },
    {
      "id": "term:lithium-metal-battery",
      "type": "Term",
      "label": "Lithium-metal battery",
      "properties": {
        "id": "lithium-metal-battery",
        "name": "Lithium-metal battery",
        "section": "topic-other-chemistries",
        "definition": "A rechargeable cell whose negative electrode is lithium metal rather than a host material. It promises much higher energy density than lithium-ion, but lithium deposits unevenly on charge, so dendrites and short life have kept it from the mass market.",
        "related": [
          "lithium-metal-anode",
          "dendrite",
          "solid-state-battery",
          "anode-free"
        ],
        "url": "https://lemonergy.com/learn/glossary/lithium-metal-battery/",
        "mentions": [
          "electrode",
          "negative-electrode",
          "energy-density"
        ]
      }
    },
    {
      "id": "term:specific-energy",
      "type": "Term",
      "label": "Specific energy",
      "properties": {
        "id": "specific-energy",
        "name": "Specific energy",
        "aka": [
          "gravimetric energy density"
        ],
        "section": "topic-ratings",
        "definition": "Stored energy per unit mass, in watt-hours per kilogram. Commercial lithium-ion cells range from about 160 Wh/kg for LFP to around 270 Wh/kg for high-nickel chemistries; at pack level the figure drops by a quarter or more.",
        "unit": "Wh/kg",
        "related": [
          "energy-density",
          "cell-to-pack-ratio",
          "specific-capacity",
          "ragone-plot"
        ],
        "lesson": "fundamentals/capacity-and-c-rate/#energy",
        "url": "https://lemonergy.com/learn/glossary/specific-energy/",
        "mentions": []
      }
    },
    {
      "id": "term:polysulfide-shuttle",
      "type": "Term",
      "label": "Polysulfide shuttle",
      "properties": {
        "id": "polysulfide-shuttle",
        "name": "Polysulfide shuttle",
        "aka": [
          "shuttle effect",
          "polysulfide shuttle effect"
        ],
        "section": "topic-aging",
        "definition": "The parasitic loop in a lithium–sulfur cell in which long-chain polysulfides, Li₂Sₙ with n from 4 to 8, dissolve into the electrolyte, diffuse to the lithium electrode, are reduced there and diffuse back. It causes self-discharge, low coulombic efficiency and loss of sulfur; lithium nitrate, which passivates the lithium surface, is the usual additive against it.",
        "related": [
          "lithium-sulfur",
          "self-discharge",
          "coulombic-efficiency",
          "lithium-metal-anode",
          "electrolyte-additive",
          "conversion-reaction"
        ],
        "url": "https://lemonergy.com/learn/glossary/polysulfide-shuttle/",
        "mentions": [
          "electrode",
          "electrolyte"
        ]
      }
    },
    {
      "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:cycle-life",
      "type": "Term",
      "label": "Cycle life",
      "properties": {
        "id": "cycle-life",
        "name": "Cycle life",
        "section": "topic-ratings",
        "definition": "The number of full charge–discharge cycles a cell completes before its capacity falls to a stated fraction, usually 80 %, of its initial value under defined conditions. LFP cells reach several thousand cycles; high-energy NMC fewer.",
        "unit": "cycles",
        "related": [
          "end-of-life",
          "capacity-fade",
          "depth-of-discharge",
          "calendar-life",
          "equivalent-full-cycle",
          "cycle-life-test"
        ],
        "url": "https://lemonergy.com/learn/glossary/cycle-life/",
        "mentions": []
      }
    },
    {
      "id": "reference:choi-post-li",
      "type": "Reference",
      "label": "Promise and reality of post-lithium-ion batteries with high energy densities",
      "properties": {
        "title": "Promise and reality of post-lithium-ion batteries with high energy densities",
        "publisher": "Nature Reviews Materials",
        "url": "https://doi.org/10.1038/natrevmats.2016.13",
        "type": "Review article",
        "scope": "Post-lithium-ion materials and battery concepts, including practical cell-level limitations; historical 2016 perspective.",
        "year": 2016,
        "authors": [
          "Jang Wook Choi",
          "Doron Aurbach"
        ],
        "accessed": "2026-10-27"
      }
    }
  ]
}