{ "node": { "id": "term:faradays-law", "type": "Term", "label": "Faraday’s law of electrolysis", "properties": { "id": "faradays-law", "name": "Faraday’s law of electrolysis", "section": "topic-electrochemistry", "definition": "The amount of substance transformed at an electrode is proportional to the charge passed: one mole of electrons per Faraday. It converts a material’s formula into its theoretical capacity in mAh/g.", "formula": "m = Q·M / (n·F)", "related": [ "faradays-constant", "theoretical-capacity", "specific-capacity" ], "example": { "title": "Convert charge to ideal deposited mass", "text": "For a hypothetical one-electron species with molar mass 50 g/mol, transferring 1 Ah = 3600 C corresponds to about 1.87 g at 100% Faradaic efficiency. Side reactions reduce the intended deposited amount." }, "url": "https://lemonergy.com/learn/glossary/faradays-law/", "mentions": [ "milliampere-hour", "electrode" ] } }, "edges": [ { "id": "edge:1885", "source": "term:faradays-law", "target": "topic:topic-electrochemistry", "type": "belongsTo", "properties": { "sourceFile": "terms.json" } }, { "id": "edge:1886", "source": "term:faradays-law", "target": "term:faradays-constant", "type": "relatedTo", "properties": { "sourceFile": "terms.json", "meaning": "Related context; not a causal claim" } }, { "id": "edge:1887", "source": "term:faradays-law", "target": "term:theoretical-capacity", "type": "relatedTo", "properties": { "sourceFile": "terms.json", "meaning": "Related context; not a causal claim" } }, { "id": "edge:1888", "source": "term:faradays-law", "target": "term:specific-capacity", "type": "relatedTo", "properties": { "sourceFile": "terms.json", "meaning": "Related context; not a causal claim" } }, { "id": "edge:mentions/faradays-law/milliampere-hour", "source": "term:faradays-law", "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/faradays-law/electrode", "source": "term:faradays-law", "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:1891", "source": "term:faradays-law", "target": "visual:faraday", "type": "illustratedBy", "properties": { "sourceFile": "visual-pages.json" } }, { "id": "edge:1892", "source": "term:faradays-law", "target": "reference:iupac-green", "type": "cites", "properties": { "sourceFile": "wiki-references.json", "scope": "direct technical reference" } } ], "neighbors": [ { "id": "topic:topic-electrochemistry", "type": "Topic", "label": "Electrochemistry fundamentals", "properties": { "id": "topic-electrochemistry", "name": "Electrochemistry fundamentals", "lede": "The reactions and potentials that make a cell a battery.", "context": "Connect reaction sites and transport paths.", "example": "A circuit can predict terminal voltage while leaving electrode potentials and reaction kinetics unresolved.", "lesson_url": "https://lemonergy.com/learn/fundamentals/cell-anatomy/", "lesson_label": "Open cell anatomy" } }, { "id": "term:faradays-constant", "type": "Term", "label": "Faraday’s constant", "properties": { "id": "faradays-constant", "name": "Faraday’s constant", "abbr": "F", "section": "topic-electrochemistry", "definition": "The charge carried by one mole of electrons, 96 485 coulombs or 26.8 ampere-hours. It links the moles of lithium that move in a reaction to the ampere-hours a cell delivers.", "unit": "C/mol", "related": [ "faradays-law", "theoretical-capacity", "coulomb", "ampere-hour" ], "url": "https://lemonergy.com/learn/glossary/faradays-constant/", "mentions": [] } }, { "id": "term:theoretical-capacity", "type": "Term", "label": "Theoretical capacity", "properties": { "id": "theoretical-capacity", "name": "Theoretical capacity", "section": "topic-ratings", "definition": "The capacity a material would deliver if every available lithium ion took part, computed from Faraday’s law and the molar mass. Practical capacity is lower because not all the lithium can be removed reversibly.", "formula": "Q = n·F / (3.6·M)", "unit": "mAh/g", "related": [ "specific-capacity", "faradays-law", "faradays-constant" ], "example": { "title": "Compute a one-electron capacity", "text": "For an illustrative active material with molar mass 100 g/mol and one transferred electron per formula unit, nF/(3.6M) is about 268 mAh/g. Inactive material and incomplete utilization reduce the cell-level value." }, "url": "https://lemonergy.com/learn/glossary/theoretical-capacity/", "mentions": [] } }, { "id": "term:specific-capacity", "type": "Term", "label": "Specific capacity", "properties": { "id": "specific-capacity", "name": "Specific capacity", "section": "topic-ratings", "definition": "Charge stored per gram of active material, in mAh/g. It is the figure materials scientists quote: about 150–200 mAh/g for layered oxides, 160 for LFP, 372 theoretical for graphite and about 3600 for silicon.", "unit": "mAh/g", "related": [ "theoretical-capacity", "active-material", "specific-energy", "faradays-law" ], "url": "https://lemonergy.com/learn/glossary/specific-capacity/", "mentions": [ "milliampere-hour", "graphite" ] } }, { "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: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": "visual:faraday", "type": "Visual", "label": "Charge counts reaction equivalents", "properties": { "title": "Charge counts reaction equivalents", "summary": "Electron count and molar mass connect electrical charge to transformed material.", "readout": "268 mAh/g for 1 electron(s) and 100 g/mol.", "formula": "Q_theoretical = nF / (3.6M); m = charge × M / (nF)", "note": "Assumes complete Faradaic conversion and 100% utilization. Practical reversible capacity can be lower; the material identity is not inferred from molar mass.", "software": { "status": "reference", "label": "Reference concept", "body": "battery-core has no Faraday-law material calculator. The relationship helps interpret active-material capacity before cell-specific utilization is considered.", "href": "../chapter-1/" }, "html": "
Theoretical capacity and molar mass
Theoretical capacity and molar massMolar mass (g/mol) versus Theoretical capacity (mAh/g). Ideal specific capacity. Interpretation follows the graphs.020335906701601,0102301,340300Molar mass (g/mol)Theoretical capacity(mAh/g)
Ideal specific capacity
\n
Mass transformed by charge
Mass transformed by chargeTransferred charge (Ah) versus Transformed mass (g). Reaction-equivalent mass. Interpretation follows the graphs.004.661.259.332.5143.7518.75Transferred charge (Ah)Transformed mass (g)
Reaction-equivalent mass
" } }, { "id": "reference:iupac-green", "type": "Reference", "label": "Quantities, Units and Symbols in Physical Chemistry, 3rd edition, 2nd printing", "properties": { "title": "Quantities, Units and Symbols in Physical Chemistry, 3rd edition, 2nd printing", "publisher": "IUPAC", "url": "https://media.iupac.org/publications/books/gbook/IUPAC-GB3-2ndPrinting-Online-22apr2011.pdf", "type": "Technical reference", "scope": "Physical-chemistry notation, thermodynamics, electrochemistry and transport quantities.", "year": 2011, "accessed": "2026-10-27" } } ] }