{
"node": {
"id": "term:differential-voltage-analysis",
"type": "Term",
"label": "Differential voltage analysis",
"properties": {
"id": "differential-voltage-analysis",
"name": "Differential voltage analysis",
"abbr": "DVA",
"aka": [
"dV/dQ"
],
"section": "topic-state",
"definition": "Plotting the derivative of voltage with respect to charge during a slow cycle. Its peaks mark electrode phase transitions, and how they shift between cycles separates lithium inventory loss from active-material loss without opening the cell.",
"formula": "dV/dQ vs Q",
"related": [
"incremental-capacity-analysis",
"loss-of-lithium-inventory",
"loss-of-active-material",
"phase-transition"
],
"example": {
"title": "Interpret a local slope",
"text": "If voltage changes by 0.020 V over 0.10 Ah in a slowly measured region, the local slope is approximately 0.20 V/Ah. Comparing curves requires consistent current, temperature, sampling and preprocessing."
},
"url": "https://lemonergy.com/learn/glossary/differential-voltage-analysis/",
"mentions": [
"electrode"
]
}
},
"edges": [
{
"id": "edge:1316",
"source": "term:differential-voltage-analysis",
"target": "topic:topic-state",
"type": "belongsTo",
"properties": {
"sourceFile": "terms.json"
}
},
{
"id": "edge:1317",
"source": "term:differential-voltage-analysis",
"target": "term:incremental-capacity-analysis",
"type": "relatedTo",
"properties": {
"sourceFile": "terms.json",
"meaning": "Related context; not a causal claim"
}
},
{
"id": "edge:1318",
"source": "term:differential-voltage-analysis",
"target": "term:loss-of-lithium-inventory",
"type": "relatedTo",
"properties": {
"sourceFile": "terms.json",
"meaning": "Related context; not a causal claim"
}
},
{
"id": "edge:1319",
"source": "term:differential-voltage-analysis",
"target": "term:loss-of-active-material",
"type": "relatedTo",
"properties": {
"sourceFile": "terms.json",
"meaning": "Related context; not a causal claim"
}
},
{
"id": "edge:1320",
"source": "term:differential-voltage-analysis",
"target": "term:phase-transition",
"type": "relatedTo",
"properties": {
"sourceFile": "terms.json",
"meaning": "Related context; not a causal claim"
}
},
{
"id": "edge:mentions/differential-voltage-analysis/electrode",
"source": "term:differential-voltage-analysis",
"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:1322",
"source": "term:differential-voltage-analysis",
"target": "visual:voltage-derivatives",
"type": "illustratedBy",
"properties": {
"sourceFile": "visual-pages.json"
}
}
],
"neighbors": [
{
"id": "topic:topic-state",
"type": "Topic",
"label": "State estimation",
"properties": {
"id": "topic-state",
"name": "State estimation",
"lede": "The quantities a battery management system estimates but cannot measure directly.",
"context": "Distinguish internal states from noisy measurement estimates.",
"example": "Current-sensor bias accumulates in coulomb counting. Exact model SOC does not establish real estimator accuracy.",
"lesson_url": "https://lemonergy.com/learn/fundamentals/capacity-and-c-rate/",
"lesson_label": "Open charge balance"
}
},
{
"id": "term:incremental-capacity-analysis",
"type": "Term",
"label": "Incremental capacity analysis",
"properties": {
"id": "incremental-capacity-analysis",
"name": "Incremental capacity analysis",
"abbr": "ICA",
"aka": [
"dQ/dV"
],
"section": "topic-state",
"definition": "The inverse of differential voltage analysis: the derivative of charge with respect to voltage, plotted against voltage. Plateaus in the voltage curve become peaks whose height and position track aging, and it can be run on data a BMS already records.",
"formula": "dQ/dV vs V",
"related": [
"differential-voltage-analysis",
"voltage-plateau",
"state-of-health"
],
"example": {
"title": "Read capacity per voltage interval",
"text": "If 0.10 Ah is transferred while voltage rises by 0.020 V, the local incremental capacity is about 5 Ah/V. Numerical differentiation can amplify noise, so a peak must be assessed with the measurement conditions."
},
"url": "https://lemonergy.com/learn/glossary/incremental-capacity-analysis/",
"mentions": [
"discharge-curve",
"bms"
]
}
},
{
"id": "term:loss-of-lithium-inventory",
"type": "Term",
"label": "Loss of lithium inventory",
"properties": {
"id": "loss-of-lithium-inventory",
"name": "Loss of lithium inventory",
"abbr": "LLI",
"section": "topic-aging",
"definition": "The degradation mode in which cyclable lithium is consumed by side reactions — SEI growth, plating, electrolyte decomposition — and can no longer shuttle between the electrodes. It is the dominant cause of capacity fade in most lithium-ion cells.",
"related": [
"sei",
"lithium-plating",
"capacity-fade",
"loss-of-active-material",
"coulombic-efficiency"
],
"url": "https://lemonergy.com/learn/glossary/loss-of-lithium-inventory/",
"mentions": [
"electrolyte",
"aging-mechanism",
"electrolyte-decomposition"
]
}
},
{
"id": "term:loss-of-active-material",
"type": "Term",
"label": "Loss of active material",
"properties": {
"id": "loss-of-active-material",
"name": "Loss of active material",
"abbr": "LAM",
"section": "topic-aging",
"definition": "The degradation mode in which electrode material becomes unable to store lithium: particles crack and lose electronic contact, structures collapse, or transition metals dissolve. It is tracked separately for each electrode.",
"related": [
"particle-cracking",
"transition-metal-dissolution",
"loss-of-lithium-inventory",
"capacity-fade"
],
"url": "https://lemonergy.com/learn/glossary/loss-of-active-material/",
"mentions": [
"electrode",
"aging-mechanism"
]
}
},
{
"id": "term:phase-transition",
"type": "Term",
"label": "Phase transition",
"properties": {
"id": "phase-transition",
"name": "Phase transition",
"aka": [
"staging"
],
"section": "topic-electrochemistry",
"definition": "A change of crystal structure as lithium content varies, which fixes the potential while two phases coexist. Graphite fills in stages, LFP switches between two phases across almost its whole range, and these transitions make the peaks that aging diagnostics read.",
"related": [
"voltage-plateau",
"differential-voltage-analysis",
"lfp",
"graphite",
"structural-degradation"
],
"url": "https://lemonergy.com/learn/glossary/phase-transition/",
"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": "visual:voltage-derivatives",
"type": "Visual",
"label": "A voltage plateau becomes an ICA peak",
"properties": {
"title": "A voltage plateau becomes an ICA peak",
"summary": "Differentiate an authored monotonic voltage curve to see the information in DVA and ICA.",
"readout": "At the plateau center, dV/dq = 0.44 V per charge fraction; dq/dV = 2.273 charge fraction/V.",
"formula": "DVA = dV/dq; ICA = dq/dV = 1 / (dV/dq), q = Q/Q_nominal",
"note": "Normalized authored curve, not a measured cell fingerprint. Peak changes alone do not uniquely identify a degradation mechanism.",
"software": {
"status": "reference",
"label": "Reference concept",
"body": "These derivatives illustrate the analysis. battery-core does not extract aging mechanisms from measured voltage data; real differentiation needs sampling and noise treatment.",
"href": "../chapter-1/"
},
"html": "Authored voltage curve