Cells#

A cell is one physical item with a serial number; this page covers how many cells reference one spec, and how a cell-spec is described from reusable parts: it references standalone component-specs by IRI, which in turn reference material-specs — completing the three-level graph cell → component → material.

Reference seam#

A cell-spec gains five optional top-level reference fields (siblings of the inline positive_electrode/electrolyte/… holders):

Field	Resolves to
`positive_electrode_spec_id` / `negative_electrode_spec_id`	`electrode-spec`
`electrolyte_spec_id`	`electrolyte-spec`
`separator_spec_id`	`separator-spec`
`housing_spec_id`	`housing-spec`

A cell may reference, inline, or both — inline holders stay optional, so existing records are unaffected. References are existence-checked against the source root, and the JSON-LD emits reference nodes (hasPositiveElectrode: {"@id": <electrode-spec IRI>}, etc.); when a basis/inline node is also present, the @id is merged onto it.

import battinfo as bi

rec = bi.save_cell_spec(bi.CellSpec(
    model_name="COIN-NMC811-D", manufacturer="EMPA", format="coin", chemistry="Li-ion",
    positive_electrode_spec_id=NMC811_CATHODE_IRI,
    negative_electrode_spec_id=GRAPHITE_ANODE_IRI,
    electrolyte_spec_id=ORGANIC_ELECTROLYTE_IRI,
    separator_spec_id=CELGARD_IRI,
    housing_spec_id=COIN_HOUSING_IRI,
    properties={"nominal_capacity": {"value": 0.0038, "unit": "Ah"}, "nominal_voltage": {"value": 3.8, "unit": "V"}},
), source_root="examples")

Bridge (inline → standalone)#

extract_component_specs(cell_spec_record) lifts a cell’s inline holders into standalone component-specs (the counterpart of extract_material_specs), so any inline cell can be decomposed and de-duplicated.

The fleet (reference-based)#

examples/cell-spec/ adds 8 cells that reference shared component-specs by IRI:

Cell	format	chemistry	grounding
COIN-NMC811-D	coin	Li-ion (NMC811)	Discovery
COIN-LFP-D	coin	Li-ion (LFP)	Discovery
COIN-LCO-D	coin	Li-ion (LCO)	Discovery
COIN-LMFP-D	coin	Li-ion (LMFP)	Discovery
COIN-NMC622-D	coin	Li-ion (NMC622)	Discovery
PRISM-LFP-100AH	prismatic	Li-ion (LFP)	Cell_Design (engineering)
COIN-ZNMNO2-ALK	coin	Zn-MnO2 alkaline	synthetic (7M KOH, non-Li-ion)
COIN-LNMO-D	coin	Li-ion (LNMO)	synthetic (high-voltage)

The component fleet was extended with one cathode electrode-spec per chemistry (LFP/LCO/LMFP/NMC622/LNMO/MnO2 cathodes, Zn anode) and an MnO2 material-spec; the graphite anode, organic + aqueous electrolytes, Celgard separator, and coin/prismatic housings are shared across cells.

Full-graph showcase#

The NMC811 coin demonstrates the complete graph end-to-end:

cell-spec COIN-NMC811-D  →  cell-instance (P025-CEL-001)  →  test (cycling)  →  dataset
        ↓ references
   electrode-spec / electrolyte-spec / separator-spec / housing-spec  →  material-specs

examples/cell-instance/, examples/test/, and examples/dataset/ carry the linked instance/test/dataset for it; the broader instance/test/dataset fleet is Phase 4.