Guide 4 — The semantic layer#

This guide examines the JSON-LD that BattINFO produces, explains how it connects to EMMO, and shows how to work with it using RDF tools.

Estimated time: 20 minutes Prerequisites: Guide 2 or Guide 3

New words? The plain-language glossary decodes EMMO, IRI, JSON-LD, and the rest in two sentences each.

[1]:

import json
import warnings
from pathlib import Path

SCRATCH = Path("_scratch/guide-04")
SCRATCH.mkdir(parents=True, exist_ok=True)

from battinfo import CellSpec, publish
from battinfo.api import publish_record

cell_spec = CellSpec(
    manufacturer="A123 Systems",
    model="ANR26650M1-B",
    format="cylindrical",
    chemistry="Li-ion",
    positive_electrode_basis="LFP",
    negative_electrode_basis="graphite",
    size_code="R26650",
    properties={
        "nominal_capacity":   {"value": 2.5,  "unit": "Ah"},
        "nominal_voltage":    {"value": 3.3,  "unit": "V"},
        "rated_energy":       {"value": 8.25, "unit": "Wh"},
        "mass":               {"value": 76.0, "unit": "g"},
        "diameter":           {"value": 26.0, "unit": "mm"},
        "height":             {"value": 65.0, "unit": "mm"},
        "internal_resistance":{"value": 6.0,  "unit": "mΩ"},
        "cycle_life":         {"value_text": ">1000", "unit": "count"},
    },
)

result = publish(cell_spec, destination="local", root=SCRATCH)
output = publish_record(
    result.debug_paths["canonical_record_path"],
    target_root=SCRATCH / "resolver",
)

jsonld_path = Path(output["output_dir"], "index.jsonld")
jsonld = json.loads(jsonld_path.read_text(encoding="utf-8"))
print("Ready. IRI:", result.canonical_iri)

<repo>\src\battinfo\transform\cell_spec_node.py:483: UserWarning: semantic.value_text_only: 'cycle_life' on https://w3id.org/battinfo/spec/wckm-y5a4-he0k-2scd carries only value_text - the JSON-LD export emits no numeric quantity value for it.
  property_nodes = cell_spec_property_nodes(
<repo>\src\battinfo\transform\cell_spec_node.py:483: UserWarning: semantic.value_text_only: 'cycle_life' on https://w3id.org/battinfo/spec/wckm-y5a4-he0k-2scd carries only value_text - the JSON-LD export emits no numeric quantity value for it.
  property_nodes = cell_spec_property_nodes(
<repo>\src\battinfo\transform\cell_spec_node.py:483: UserWarning: semantic.value_text_only: 'cycle_life' on https://w3id.org/battinfo/spec/wckm-y5a4-he0k-2scd carries only value_text - the JSON-LD export emits no numeric quantity value for it.
  property_nodes = cell_spec_property_nodes(
<repo>\src\battinfo\transform\cell_spec_node.py:483: UserWarning: semantic.value_text_only: 'cycle_life' on https://w3id.org/battinfo/spec/wckm-y5a4-he0k-2scd carries only value_text - the JSON-LD export emits no numeric quantity value for it.
  property_nodes = cell_spec_property_nodes(

Ready. IRI: https://w3id.org/battinfo/spec/wckm-y5a4-he0k-2scd

The full resolver JSON-LD#

[2]:

print(json.dumps(jsonld, indent=2))

{
  "@context": [
    "https://w3id.org/emmo/domain/battery/context",
    {
      "schema": "https://schema.org/",
      "csvw": "http://www.w3.org/ns/csvw#",
      "battinfo": "https://w3id.org/battinfo/",
      "skos": "http://www.w3.org/2004/02/skos/core#"
    }
  ],
  "@type": [
    "BatteryCellSpecification",
    "schema:CreativeWork"
  ],
  "@id": "https://w3id.org/battinfo/spec/wckm-y5a4-he0k-2scd",
  "schema:identifier": "wckm-y5a4-he0k-2scd",
  "schema:name": "A123 Systems ANR26650M1-B",
  "schema:model": "ANR26650M1-B",
  "schema:manufacturer": {
    "@type": "schema:Organization",
    "schema:name": "A123 Systems"
  },
  "schema:url": "https://www.battery-genome.org/registry/spec/wckm-y5a4-he0k-2scd",
  "isDescriptionFor": {
    "@type": [
      "BatteryCell",
      "CylindricalBattery",
      "LithiumIonBattery",
      "LithiumIonIronPhosphateBattery",
      "LithiumIonGraphiteBattery"
    ],
    "skos:prefLabel": "A123 Systems ANR26650M1-B"
  },
  "schema:size": "R26650",
  "schema:schemaVersion": "0.2.0",
  "hasProperty": [
    {
      "@type": [
        "NominalCapacity",
        "ConventionalProperty"
      ],
      "skos:prefLabel": "NominalCapacity",
      "hasNumericalPart": {
        "@type": "RealData",
        "hasNumberValue": 2.5
      },
      "hasMeasurementUnit": "https://w3id.org/emmo#AmpereHour"
    },
    {
      "@type": [
        "NominalVoltage",
        "ConventionalProperty"
      ],
      "skos:prefLabel": "NominalVoltage",
      "hasNumericalPart": {
        "@type": "RealData",
        "hasNumberValue": 3.3
      },
      "hasMeasurementUnit": "https://w3id.org/emmo#Volt"
    },
    {
      "@type": [
        "NominalEnergy",
        "ConventionalProperty"
      ],
      "skos:prefLabel": "NominalEnergy",
      "hasNumericalPart": {
        "@type": "RealData",
        "hasNumberValue": 8.25
      },
      "hasMeasurementUnit": "https://w3id.org/emmo#Watthour"
    },
    {
      "@type": [
        "Mass",
        "ConventionalProperty"
      ],
      "skos:prefLabel": "Mass",
      "hasNumericalPart": {
        "@type": "RealData",
        "hasNumberValue": 76.0
      },
      "hasMeasurementUnit": "https://w3id.org/emmo#Gram"
    },
    {
      "@type": [
        "Diameter",
        "ConventionalProperty"
      ],
      "skos:prefLabel": "Diameter",
      "hasNumericalPart": {
        "@type": "RealData",
        "hasNumberValue": 26.0
      },
      "hasMeasurementUnit": "https://w3id.org/emmo#MilliMetre"
    },
    {
      "@type": [
        "Height",
        "ConventionalProperty"
      ],
      "skos:prefLabel": "Height",
      "hasNumericalPart": {
        "@type": "RealData",
        "hasNumberValue": 65.0
      },
      "hasMeasurementUnit": "https://w3id.org/emmo#MilliMetre"
    },
    {
      "@type": [
        "InternalResistance",
        "ConventionalProperty"
      ],
      "skos:prefLabel": "InternalResistance",
      "hasNumericalPart": {
        "@type": "RealData",
        "hasNumberValue": 6.0
      },
      "hasMeasurementUnit": "https://w3id.org/emmo#MilliOhm"
    },
    {
      "@type": [
        "CycleLife",
        "ConventionalProperty"
      ],
      "skos:prefLabel": "CycleLife",
      "schema:value": ">1000",
      "hasMeasurementUnit": "https://w3id.org/emmo#EMMO_5ebd5e01_0ed3_49a2_a30d_cd05cbe72978"
    }
  ],
  "hasPositiveElectrode": {
    "@type": "LithiumIronPhosphateElectrode"
  },
  "hasNegativeElectrode": {
    "@type": "GraphiteElectrode"
  },
  "dcterms:source": {
    "@type": "prov:Entity",
    "dcterms:type": "datasheet",
    "prov:generatedAtTime": "2026-08-04T01:23:12+00:00"
  }
}

`@context`#

Maps short names to full IRIs. Every term — BatteryCell, hasNumericalPart, NominalCapacity — resolves to a UUID-based IRI in the EMMO domain-battery ontology. BattINFO bundles a local copy so processing works offline.

`@id`#

The permanent IRI for this cell spec, resolvable at https://w3id.org/battinfo/spec/{uid}.

`@type` stacking#

[3]:

print("@type classes:")
for t in jsonld["@type"]:
    print(f"  {t}")

@type classes:
  BatteryCellSpecification
  schema:CreativeWork

The specification node (BatteryCellSpecification) carries two types:

Vocabulary	Type	Rationale
EMMO	`BatteryCellSpecification`	Information entity describing a class of cells
schema.org	`schema:CreativeWork`	The specification document as a creative artifact

The physical EMMO classes derived from cell-spec fields are placed on an isDescriptionFor anonymous node:

Source field	Physical EMMO class (on `isDescriptionFor`)
`format: "cylindrical"`	`CylindricalBattery`
`chemistry: "Li-ion"`	`LithiumIonBattery`
`positive_electrode_basis: "LFP"`	`LithiumIonIronPhosphateBattery`
`negative_electrode_basis: "graphite"`	`LithiumIonGraphiteBattery`
(always)	`BatteryCell`

Placing physical types on isDescriptionFor is semantically correct: the specification is an information entity, not a physical cell. The old pattern (putting BatteryCell directly on the specification @type) implied the specification IS a physical cell, which is wrong.

No manual annotation — derived entirely from plain-text field values.

`hasProperty` — the canonical EMMO quantity pattern#

`isDescriptionFor` — where physical EMMO types live#

The resolver JSON-LD above is a lightweight discovery document — it omits the physical type stacking to keep file size small. The full descriptor JSON-LD (produced by to_jsonld) includes an isDescriptionFor anonymous node that carries the physical EMMO classes:

This placement is semantically correct: the specification is an information entity, not a physical cell. Putting BatteryCell on the specification @type would assert the specification IS a physical cell — which is wrong.

`hasDescription` — the reverse link from cell instance to specification#

Cell instances (physical objects with serial numbers) carry hasDescription pointing to the specification IRI, plus schema:isVariantOf for schema.org alignment:

The directionality reflects how data is created: the cell spec is registered first and given a stable IRI; individual cells with serial numbers are created later and reference it. Both hasDescription (EMMO) and schema:isVariantOf (schema.org) express the same relationship in their respective vocabularies.

[4]:

# Show isDescriptionFor from the full descriptor pipeline
from battinfo.transform.json_to_jsonld import _descriptor_specification_to_jsonld

spec = {
    "format": "cylindrical",
    "chemistry": "Li-ion",
    "positive_electrode_basis": "LFP",
    "negative_electrode_basis": "graphite",
}
node = _descriptor_specification_to_jsonld(spec)

print("Specification @type:", node["@type"])
print("isDescriptionFor @type:", node["isDescriptionFor"]["@type"])

Specification @type: ['BatteryCellSpecification', 'schema:CreativeWork']
isDescriptionFor @type: ['BatteryCell', 'CylindricalBattery', 'LithiumIonBattery', 'LithiumIonIronPhosphateBattery', 'LithiumIonGraphiteBattery']

[5]:

print("Quantitative properties:")
for prop in jsonld.get("hasProperty", []):
    types = prop["@type"]
    class_name = types[0] if isinstance(types, list) else types
    value = prop.get("hasNumericalPart", {}).get("hasNumberValue")
    unit  = prop.get("hasMeasurementUnit", "").split("#")[-1]
    print(f"  {class_name}: {value}  ({unit})")

Quantitative properties:
  NominalCapacity: 2.5  (AmpereHour)
  NominalVoltage: 3.3  (Volt)
  NominalEnergy: 8.25  (Watthour)
  Mass: 76.0  (Gram)
  Diameter: 26.0  (MilliMetre)
  Height: 65.0  (MilliMetre)
  InternalResistance: 6.0  (MilliOhm)
  CycleLife: None  (EMMO_5ebd5e01_0ed3_49a2_a30d_cd05cbe72978)

The pattern is:

hasProperty → NominalCapacity, ConventionalProperty
                ├── hasNumericalPart → RealData → hasNumericalValue: 2.5
                └── hasMeasurementUnit: <EMMO AmpereHour IRI>

This is the canonical EMMO quantity pattern — identical across all EMMO domain modules.

Validating JSON-LD#

[6]:

from battinfo.validate.jsonld import validate_jsonld_report

report = validate_jsonld_report(jsonld)
print("ok:", report.ok)
for issue in report.issues:
    print(f"  [{issue.severity}] {issue.code}: {issue.message}")

ok: True

Check	What fails
`@type` term check	Bare `@type` value not in EMMO context
RDF parse	JSON-LD rdflib cannot parse into a valid RDF dataset
URDNA2015	JSON-LD that cannot be canonically normalised

Loading into an RDF graph#

[7]:

from rdflib import Graph

g = Graph()
with warnings.catch_warnings():
    warnings.filterwarnings("ignore", category=DeprecationWarning, module="rdflib")
    g.parse(str(jsonld_path), format="json-ld")

print(f"Triple count: {len(g)}")

Triple count: 88

[8]:

# All triples in the graph
for s, p, o in sorted(g):
    s_l = str(s).split("/")[-1].split("#")[-1]
    p_l = str(p).split("/")[-1].split("#")[-1]
    o_l = str(o).split("/")[-1].split("#")[-1]
    print(f"  {s_l}  →  {p_l}  →  {o_l}")

  N0379cdffbf56498b845455ef78356a80  →  type  →  electrochemistry_c831d963_629a_41ab_850f_97fb6841b739
  N051aff4ca3fd4b0f9b003e255976ac07  →  type  →  EMMO_d8aa8e1f_b650_416d_88a0_5118de945456
  N051aff4ca3fd4b0f9b003e255976ac07  →  type  →  electrochemistry_8abde9d0_84f6_4b4f_a87e_86028a397100
  N051aff4ca3fd4b0f9b003e255976ac07  →  prefLabel  →  NominalCapacity
  N051aff4ca3fd4b0f9b003e255976ac07  →  EMMO_8ef3cd6d_ae58_4a8d_9fc0_ad8f49015cd0  →  N9c8620a4df5f4cdabafdfbc1feb23222
  N051aff4ca3fd4b0f9b003e255976ac07  →  EMMO_bed1d005_b04e_4a90_94cf_02bc678a8569  →  AmpereHour
  N195dca1978fa4907bb2454b411a6febe  →  type  →  EMMO_d8aa8e1f_b650_416d_88a0_5118de945456
  N195dca1978fa4907bb2454b411a6febe  →  type  →  electrochemistry_19e27aa3_0970_43a6_86d3_e3cdd956134d
  N195dca1978fa4907bb2454b411a6febe  →  prefLabel  →  NominalEnergy
  N195dca1978fa4907bb2454b411a6febe  →  EMMO_8ef3cd6d_ae58_4a8d_9fc0_ad8f49015cd0  →  N497e106d520f4124a5978412fea2aa66
  N195dca1978fa4907bb2454b411a6febe  →  EMMO_bed1d005_b04e_4a90_94cf_02bc678a8569  →  Watthour
  N19dc2630a90a41569cc5371906b9cc91  →  type  →  EMMO_18d180e4_5e3e_42f7_820c_e08951223486
  N19dc2630a90a41569cc5371906b9cc91  →  EMMO_faf79f53_749d_40b2_807c_d34244c192f4  →  6.0
  N1e78ca3bc69b4ba0bce274349ad42c94  →  type  →  Organization
  N1e78ca3bc69b4ba0bce274349ad42c94  →  name  →  A123 Systems
  N2d516272fe7f41cc8e3312ee57f9b37b  →  type  →  EMMO_18d180e4_5e3e_42f7_820c_e08951223486
  N2d516272fe7f41cc8e3312ee57f9b37b  →  EMMO_faf79f53_749d_40b2_807c_d34244c192f4  →  26.0
  N3bbf8bfe66ec4447845db91f37ebda0d  →  type  →  EMMO_d8aa8e1f_b650_416d_88a0_5118de945456
  N3bbf8bfe66ec4447845db91f37ebda0d  →  type  →  electrochemistry_9bf40017_3f58_4030_ada7_cb37a3dfda2d
  N3bbf8bfe66ec4447845db91f37ebda0d  →  prefLabel  →  InternalResistance
  N3bbf8bfe66ec4447845db91f37ebda0d  →  EMMO_8ef3cd6d_ae58_4a8d_9fc0_ad8f49015cd0  →  N19dc2630a90a41569cc5371906b9cc91
  N3bbf8bfe66ec4447845db91f37ebda0d  →  EMMO_bed1d005_b04e_4a90_94cf_02bc678a8569  →  MilliOhm
  N456f5accc3b54ea495f0f7a147b0095f  →  type  →  EMMO_c1c8ac3c_8a1c_4777_8e0b_14c1f9f9b0c6
  N456f5accc3b54ea495f0f7a147b0095f  →  type  →  EMMO_d8aa8e1f_b650_416d_88a0_5118de945456
  N456f5accc3b54ea495f0f7a147b0095f  →  prefLabel  →  Diameter
  N456f5accc3b54ea495f0f7a147b0095f  →  EMMO_8ef3cd6d_ae58_4a8d_9fc0_ad8f49015cd0  →  N2d516272fe7f41cc8e3312ee57f9b37b
  N456f5accc3b54ea495f0f7a147b0095f  →  EMMO_bed1d005_b04e_4a90_94cf_02bc678a8569  →  MilliMetre
  N497e106d520f4124a5978412fea2aa66  →  type  →  EMMO_18d180e4_5e3e_42f7_820c_e08951223486
  N497e106d520f4124a5978412fea2aa66  →  EMMO_faf79f53_749d_40b2_807c_d34244c192f4  →  8.25
  N55c9e5e50bb44587a486de33d95fa306  →  type  →  EMMO_18d180e4_5e3e_42f7_820c_e08951223486
  N55c9e5e50bb44587a486de33d95fa306  →  EMMO_faf79f53_749d_40b2_807c_d34244c192f4  →  3.3
  N5c481096881545b59361c4d27990dda3  →  type  →  battery_04a4e5a4_e6fd_43af_b1ca_4a16d5f8886c
  N5c481096881545b59361c4d27990dda3  →  type  →  battery_2018e0da_4c25_46e9_83db_38431fc81ce0
  N5c481096881545b59361c4d27990dda3  →  type  →  battery_68ed592a_7924_45d0_a108_94d6275d57f0
  N5c481096881545b59361c4d27990dda3  →  type  →  battery_96addc62_ea04_449a_8237_4cd541dd8e5f
  N5c481096881545b59361c4d27990dda3  →  type  →  battery_ac604ecd_cc60_4b98_b57c_74cd5d3ccd40
  N5c481096881545b59361c4d27990dda3  →  prefLabel  →  A123 Systems ANR26650M1-B
  N8778da101e33437a819722129256db43  →  type  →  electrochemistry_1d0f15cb_d6b5_4c27_89ca_fe78adc1ce5b
  N9c8620a4df5f4cdabafdfbc1feb23222  →  type  →  EMMO_18d180e4_5e3e_42f7_820c_e08951223486
  N9c8620a4df5f4cdabafdfbc1feb23222  →  EMMO_faf79f53_749d_40b2_807c_d34244c192f4  →  2.5
  Na77d40d4f9414abc871b674d57b5d363  →  type  →  EMMO_18d180e4_5e3e_42f7_820c_e08951223486
  Na77d40d4f9414abc871b674d57b5d363  →  EMMO_faf79f53_749d_40b2_807c_d34244c192f4  →  65.0
  Nb0b92f5cbfe94deb9b808486f2022a5a  →  type  →  EMMO_18d180e4_5e3e_42f7_820c_e08951223486
  Nb0b92f5cbfe94deb9b808486f2022a5a  →  EMMO_faf79f53_749d_40b2_807c_d34244c192f4  →  76.0
  Ncd6d4f59e150403da2498c816083db39  →  type  →  EMMO_d8aa8e1f_b650_416d_88a0_5118de945456
  Ncd6d4f59e150403da2498c816083db39  →  type  →  electrochemistry_639b844a_e801_436b_985d_28926129ead6
  Ncd6d4f59e150403da2498c816083db39  →  prefLabel  →  NominalVoltage
  Ncd6d4f59e150403da2498c816083db39  →  EMMO_8ef3cd6d_ae58_4a8d_9fc0_ad8f49015cd0  →  N55c9e5e50bb44587a486de33d95fa306
  Ncd6d4f59e150403da2498c816083db39  →  EMMO_bed1d005_b04e_4a90_94cf_02bc678a8569  →  Volt
  Nddf9e8118187406bb18e2aec6b61f228  →  type  →  EMMO_d8aa8e1f_b650_416d_88a0_5118de945456
  Nddf9e8118187406bb18e2aec6b61f228  →  type  →  electrochemistry_ae782b14_88ce_4cdd_9418_12aca00be937
  Nddf9e8118187406bb18e2aec6b61f228  →  prefLabel  →  CycleLife
  Nddf9e8118187406bb18e2aec6b61f228  →  value  →  >1000
  Nddf9e8118187406bb18e2aec6b61f228  →  EMMO_bed1d005_b04e_4a90_94cf_02bc678a8569  →  EMMO_5ebd5e01_0ed3_49a2_a30d_cd05cbe72978
  Ne1a2af9c01654dfdb6437dfc5b2c21cd  →  type  →  EMMO_d8aa8e1f_b650_416d_88a0_5118de945456
  Ne1a2af9c01654dfdb6437dfc5b2c21cd  →  type  →  EMMO_ed4af7ae_63a2_497e_bb88_2309619ea405
  Ne1a2af9c01654dfdb6437dfc5b2c21cd  →  prefLabel  →  Mass
  Ne1a2af9c01654dfdb6437dfc5b2c21cd  →  EMMO_8ef3cd6d_ae58_4a8d_9fc0_ad8f49015cd0  →  Nb0b92f5cbfe94deb9b808486f2022a5a
  Ne1a2af9c01654dfdb6437dfc5b2c21cd  →  EMMO_bed1d005_b04e_4a90_94cf_02bc678a8569  →  Gram
  Nf39dfa163c1c428f8e9a60116509bc8b  →  type  →  datasheet
  Nf39dfa163c1c428f8e9a60116509bc8b  →  type  →  Entity
  Nf39dfa163c1c428f8e9a60116509bc8b  →  generatedAtTime  →  2026-08-04T01:23:12+00:00
  Nfea1b7fb6b6b41c6b9064eea68ad52a4  →  type  →  EMMO_08bcf1d6_e719_46c8_bb21_24bc9bf34dba
  Nfea1b7fb6b6b41c6b9064eea68ad52a4  →  type  →  EMMO_d8aa8e1f_b650_416d_88a0_5118de945456
  Nfea1b7fb6b6b41c6b9064eea68ad52a4  →  prefLabel  →  Height
  Nfea1b7fb6b6b41c6b9064eea68ad52a4  →  EMMO_8ef3cd6d_ae58_4a8d_9fc0_ad8f49015cd0  →  Na77d40d4f9414abc871b674d57b5d363
  Nfea1b7fb6b6b41c6b9064eea68ad52a4  →  EMMO_bed1d005_b04e_4a90_94cf_02bc678a8569  →  MilliMetre
  wckm-y5a4-he0k-2scd  →  source  →  Nf39dfa163c1c428f8e9a60116509bc8b
  wckm-y5a4-he0k-2scd  →  type  →  CreativeWork
  wckm-y5a4-he0k-2scd  →  type  →  battery_1cfbba6c_8824_4932_a23e_2141483acef7
  wckm-y5a4-he0k-2scd  →  identifier  →  wckm-y5a4-he0k-2scd
  wckm-y5a4-he0k-2scd  →  manufacturer  →  N1e78ca3bc69b4ba0bce274349ad42c94
  wckm-y5a4-he0k-2scd  →  model  →  ANR26650M1-B
  wckm-y5a4-he0k-2scd  →  name  →  A123 Systems ANR26650M1-B
  wckm-y5a4-he0k-2scd  →  schemaVersion  →  0.2.0
  wckm-y5a4-he0k-2scd  →  size  →  R26650
  wckm-y5a4-he0k-2scd  →  url  →  wckm-y5a4-he0k-2scd
  wckm-y5a4-he0k-2scd  →  EMMO_e1097637_70d2_4895_973f_2396f04fa204  →  N051aff4ca3fd4b0f9b003e255976ac07
  wckm-y5a4-he0k-2scd  →  EMMO_e1097637_70d2_4895_973f_2396f04fa204  →  N195dca1978fa4907bb2454b411a6febe
  wckm-y5a4-he0k-2scd  →  EMMO_e1097637_70d2_4895_973f_2396f04fa204  →  N3bbf8bfe66ec4447845db91f37ebda0d
  wckm-y5a4-he0k-2scd  →  EMMO_e1097637_70d2_4895_973f_2396f04fa204  →  N456f5accc3b54ea495f0f7a147b0095f
  wckm-y5a4-he0k-2scd  →  EMMO_e1097637_70d2_4895_973f_2396f04fa204  →  Ncd6d4f59e150403da2498c816083db39
  wckm-y5a4-he0k-2scd  →  EMMO_e1097637_70d2_4895_973f_2396f04fa204  →  Nddf9e8118187406bb18e2aec6b61f228
  wckm-y5a4-he0k-2scd  →  EMMO_e1097637_70d2_4895_973f_2396f04fa204  →  Ne1a2af9c01654dfdb6437dfc5b2c21cd
  wckm-y5a4-he0k-2scd  →  EMMO_e1097637_70d2_4895_973f_2396f04fa204  →  Nfea1b7fb6b6b41c6b9064eea68ad52a4
  wckm-y5a4-he0k-2scd  →  EMMO_f702bad4_fc77_41f0_a26d_79f6444fd4f3  →  N5c481096881545b59361c4d27990dda3
  wckm-y5a4-he0k-2scd  →  electrochemistry_5d299271_3f68_494f_ab96_3db9acdd3138  →  N0379cdffbf56498b845455ef78356a80
  wckm-y5a4-he0k-2scd  →  electrochemistry_8e9cf965_9f92_46e8_b678_b50410ce3616  →  N8778da101e33437a819722129256db43

Combining multiple records in one graph#

[9]:

import battinfo

ws = battinfo.workspace(root=SCRATCH / "multi")
multi_spec = battinfo.CellSpec(
    manufacturer="A123 Systems", model="ANR26650M1-B",
    format="cylindrical", chemistry="Li-ion",
    positive_electrode_basis="LFP", negative_electrode_basis="graphite",
    properties={"nominal_capacity": {"value": 2.5, "unit": "Ah"}},
)
ws.add("cell", spec=multi_spec, serial_numbers=["a123-demo-multi-001"])
ws.save()

# Publish each saved record as a resolver artifact
from battinfo.api import publish_record as _publish_one

multi_records = SCRATCH / "multi" / ".battinfo" / "records" / "examples"
multi_resolver = SCRATCH / "multi-resolver"
for record_file in sorted(multi_records.rglob("*.json")):
    _publish_one(record_file, target_root=multi_resolver)

jsonld_files = list(multi_resolver.rglob("index.jsonld"))
g2 = Graph()
with warnings.catch_warnings():
    warnings.filterwarnings("ignore", category=DeprecationWarning, module="rdflib")
    for jf in jsonld_files:
        g2.parse(str(jf), format="json-ld")

print(f"Combined graph: {len(g2)} triples from {len(jsonld_files)} files")

  cell: a123-demo-multi-001  (IRI auto-assigned)
Saved 2 record(s) under <repo>\docs\guides\_scratch\guide-04\multi\.battinfo\records:
  cell spec   A123 Systems ANR26650M1-B            [created]  .battinfo\records\cell-spec\cell-spec-e4t5-w9re-mpq6-8g7e.json
  cell        a123-demo-multi-001                  [created]  .battinfo\records\cell-instance\cell-aaqe-rvbd-c0b6-p1k3.json

  Next: ws.list(verbose=True) to inspect, or ws.publish() to publish.
Combined graph: 0 triples from 0 files

Mapping tables#

BattINFO’s semantic output is driven by three curated files:

File	Role
`assets/mappings/domain-battery/property_map.curated.json`	JSON key → EMMO class IRI
`assets/mappings/domain-battery/unit_map.curated.json`	Unit string → EMMO/QUDT IRI
`assets/mappings/domain-battery/entity_type_map.json`	format/chemistry/electrode → @type array

[10]:

prop_map = json.loads(
    # Repo files sit two levels up from this notebook.
    Path("../../assets/mappings/domain-battery/property_map.curated.json").read_text(encoding="utf-8")
)
print(f"Property map version: {prop_map['version']}")
print(f"Curated entries: {len(prop_map['mappings'])}")
print()
for entry in prop_map["mappings"][:8]:
    print(f"  {entry['key']:42s} → {entry['class_pref_label']}")
print("  ...")

Property map version: 0.4.0
Curated entries: 71

  ac_internal_resistance                     → ACInternalResistance
  available_volume                           → Volume
  calendar_life                              → CalendarLife
  cap_assembly_weight                        → Mass
  capacity_fade                              → CapacityFade
  certified_usable_energy                    → NominalEnergy
  charging_cutoff_voltage                    → UpperVoltageLimit
  charging_temperature_max                   → MaximumChargingTemperature
  ...

Next#

Guide 5 — Descriptors: author research-grade cell descriptors and see richer electrode-level JSON-LD

Guide 4 — The semantic layer#

The full resolver JSON-LD#

@context#

@id#

@type stacking#

hasProperty — the canonical EMMO quantity pattern#

isDescriptionFor — where physical EMMO types live#

hasDescription — the reverse link from cell instance to specification#