{
"node": {
"id": "term:capacitive-current",
"type": "Term",
"label": "Capacitive current",
"properties": {
"id": "capacitive-current",
"name": "Capacitive current",
"aka": [
"non-faradaic current",
"double-layer charging current"
],
"section": "topic-electrochemistry",
"definition": "Current that charges or discharges the electric double layer at an electrode without any chemical reaction, proportional to the rate of change of potential. In cyclic voltammetry it grows linearly with scan rate while diffusion-limited faradaic peaks grow with its square root, which is how the two are separated; double-layer capacitors rely on it entirely.",
"formula": "i_C = C_dl · dE/dt",
"related": [
"double-layer",
"faradaic-current",
"cyclic-voltammetry",
"supercapacitor",
"electrochemical-impedance-spectroscopy"
],
"example": {
"title": "Predict a scan-rate contribution",
"text": "For an ideal 20 μF double-layer capacitance and a potential scan of 0.10 V/s, i_C = C_dl dE/dt gives 2 μA. Faradaic current can add to this background."
},
"url": "https://lemonergy.com/learn/glossary/capacitive-current/",
"mentions": [
"electrode"
]
}
},
"edges": [
{
"id": "edge:6687",
"source": "term:capacitive-current",
"target": "topic:topic-electrochemistry",
"type": "belongsTo",
"properties": {
"sourceFile": "terms.json"
}
},
{
"id": "edge:6688",
"source": "term:capacitive-current",
"target": "term:double-layer",
"type": "relatedTo",
"properties": {
"sourceFile": "terms.json",
"meaning": "Related context; not a causal claim"
}
},
{
"id": "edge:6689",
"source": "term:capacitive-current",
"target": "term:faradaic-current",
"type": "relatedTo",
"properties": {
"sourceFile": "terms.json",
"meaning": "Related context; not a causal claim"
}
},
{
"id": "edge:6690",
"source": "term:capacitive-current",
"target": "term:cyclic-voltammetry",
"type": "relatedTo",
"properties": {
"sourceFile": "terms.json",
"meaning": "Related context; not a causal claim"
}
},
{
"id": "edge:6691",
"source": "term:capacitive-current",
"target": "term:supercapacitor",
"type": "relatedTo",
"properties": {
"sourceFile": "terms.json",
"meaning": "Related context; not a causal claim"
}
},
{
"id": "edge:6692",
"source": "term:capacitive-current",
"target": "term:electrochemical-impedance-spectroscopy",
"type": "relatedTo",
"properties": {
"sourceFile": "terms.json",
"meaning": "Related context; not a causal claim"
}
},
{
"id": "edge:mentions/capacitive-current/electrode",
"source": "term:capacitive-current",
"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:6694",
"source": "term:capacitive-current",
"target": "visual:capacitor",
"type": "illustratedBy",
"properties": {
"sourceFile": "visual-pages.json"
}
}
],
"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:double-layer",
"type": "Term",
"label": "Electric double layer",
"properties": {
"id": "double-layer",
"name": "Electric double layer",
"section": "topic-electrochemistry",
"definition": "The thin region at an electrode surface where ions in the electrolyte line up against the charge on the electrode, behaving like a capacitor. It stores a little charge without any reaction and shapes the high-frequency part of an impedance spectrum.",
"related": [
"charge-transfer",
"electrochemical-impedance-spectroscopy",
"supercapacitor"
],
"url": "https://lemonergy.com/learn/glossary/double-layer/",
"mentions": [
"impedance",
"electrode",
"electrolyte",
"capacitor"
]
}
},
{
"id": "term:faradaic-current",
"type": "Term",
"label": "Faradaic current",
"properties": {
"id": "faradaic-current",
"name": "Faradaic current",
"aka": [
"faradaic process"
],
"section": "topic-electrochemistry",
"definition": "Current carried by electron transfer in a redox reaction at an electrode, so that the charge passed and the material converted are tied together by Faraday’s law. Almost all of a battery’s capacity is faradaic; the small remainder is capacitive current that charges the double layer.",
"related": [
"capacitive-current",
"faradays-law",
"charge-transfer",
"redox-reaction",
"butler-volmer"
],
"url": "https://lemonergy.com/learn/glossary/faradaic-current/",
"mentions": [
"electrode"
]
}
},
{
"id": "term:cyclic-voltammetry",
"type": "Term",
"label": "Cyclic voltammetry",
"properties": {
"id": "cyclic-voltammetry",
"name": "Cyclic voltammetry",
"abbr": "CV",
"section": "topic-testing",
"definition": "Sweeping an electrode’s potential up and down at a fixed rate and recording the current, so each reaction shows as a peak at its potential. It is a materials-screening tool; in battery work the abbreviation CV more often means constant voltage.",
"related": [
"potentiostat",
"half-cell",
"constant-voltage",
"electrode-potential"
],
"url": "https://lemonergy.com/learn/glossary/cyclic-voltammetry/",
"mentions": [
"electrode"
]
}
},
{
"id": "term:supercapacitor",
"type": "Term",
"label": "Supercapacitor",
"properties": {
"id": "supercapacitor",
"name": "Supercapacitor",
"aka": [
"ultracapacitor",
"EDLC"
],
"section": "topic-electrochemistry",
"definition": "A device that stores charge in the electric double layer on high-surface-area carbon rather than in a reaction. It delivers very high power and lasts a million cycles but stores only a few watt-hours per kilogram.",
"related": [
"double-layer",
"specific-power",
"ragone-plot",
"hybrid-energy-storage-system"
],
"url": "https://lemonergy.com/learn/glossary/supercapacitor/",
"mentions": []
}
},
{
"id": "term:electrochemical-impedance-spectroscopy",
"type": "Term",
"label": "Electrochemical impedance spectroscopy",
"properties": {
"id": "electrochemical-impedance-spectroscopy",
"name": "Electrochemical impedance spectroscopy",
"abbr": "EIS",
"section": "topic-testing",
"definition": "Measuring a cell’s impedance across a range of frequencies, from kilohertz to millihertz, with a small alternating signal. The spectrum separates ohmic, interface and diffusion processes by their time scale and is read on a Nyquist plot.",
"related": [
"nyquist-plot",
"impedance",
"randles-circuit",
"charge-transfer",
"warburg-impedance"
],
"url": "https://lemonergy.com/learn/glossary/electrochemical-impedance-spectroscopy/",
"mentions": [
"diffusion"
]
}
},
{
"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:capacitor",
"type": "Visual",
"label": "Capacitor charge and energy",
"properties": {
"title": "Capacitor charge and energy",
"summary": "Charge rises linearly with voltage; energy rises with voltage squared.",
"readout": "At 5 V: 25 C and 62.5 J.",
"formula": "Q = CV; E = ½CV²",
"note": "Ideal constant capacitance; leakage, series resistance and voltage rating excluded.",
"software": {
"status": "reference",
"label": "Reference concept",
"body": "Q = CV and E = ½CV² explain capacitor storage. The battery nominal-energy helper alone does not simulate capacitor precharge.",
"href": "../fundamentals/battery-basics/"
},
"html": "Stored charge