Materials ========= In the Electrochemistry Domain Ontology, **materials** represent physical matter that has a defined composition, structure, and form. This includes solids, liquids, and gases — but in this section we focus primarily on *solid materials* for convenience. Materials can be raw substances (like copper or graphite), processed forms (like foils, powders, or coatings), or engineered composites (like polymer electrolytes or catalyst inks). A material can exist as part of a larger object (for example, as the active material in an electrode) or as an independent entity (for example, a powder in a storage container). Conceptual overview ------------------- In EMMO, the class `Material` sits between the purely chemical (`ChemicalSubstance`) and the physical (`PhysicalObject`) perspectives: - **ChemicalSubstance** – describes *what* the material is made of, chemically. - **Material** – describes the *physical realization* of that substance, including phase, morphology, and form. - **PhysicalObject** – describes a *specific instance* of a material existing in space and time. You can think of `Material` as the bridge between *chemistry* and *physics*: it connects chemical identity to physical form. .. admonition:: Material vs. Substance vs. Component :class: tip - **Material** → A physical manifestation of matter with properties (e.g., a zinc foil, a powder, a polymer film). - **ChemicalSubstance** → The abstract chemical identity (e.g., Zinc, LiFePO₄, H₂O). - **Component** → A role that a material plays *as part of something larger* (e.g., “the binder component” in a coating). In practice, you describe **what** it is (substance), **how** it exists (material), and **what it does** (component or role). Guidelines for Use ------------------ To represent a material using the ontology, follow three key steps: 1. **Identify the Material** Choose the appropriate subclass of `Material` or use multiple inheritance to refine meaning. For example, something that is both `Zinc` (chemical substance) and `Foil` (material form) can be declared as both. 2. **Assign Properties** Attach quantitative or qualitative properties using `hasProperty`. These may include conventional, measured, or modelled properties such as density, porosity, or conductivity. 3. **Link the Material to its Role or Context** Use domain-specific object properties like `hasActiveMaterial`, `hasBinder`, or `hasAdditive` to connect the material to another entity (for example, an `ElectrodeCoating`). Representation Patterns ----------------------- **1. Pure Substance in a Defined Form** A simple zinc foil material with basic properties. .. literalinclude:: ../../assets/jsonld/active_materials/zinc_simple.jsonld :language: json Here we combine multiple inheritance (`Zinc` and `Foil`) to indicate *what it is* and *in what form*. The density is expressed as a conventional property — taken from a datasheet rather than directly measured. **2. Material in Context — Used as an Active Material** This shows the same zinc foil linked as an **active material** in an electrode. .. literalinclude:: ../../assets/jsonld/electrodes/zinc_electrode_simple.jsonld :language: json Here, the same material description is reused in a different context through the role relation `hasActiveMaterial`. **3. Composite Material or Mixture** An electrolyte composed of multiple constituents. .. literalinclude:: ../../assets/jsonld/electrolytes/electrolyte_lp50.jsonld :language: json The solvent is a mixture of two chemical substances with a lithium salt solute. Reasoning and Reuse ------------------- Because the ontology defines `ActiveMaterial`, `Binder`, and `Additive` as subclasses of `Material`, any description that uses those roles can be automatically inferred to involve materials. For example, a reasoner will infer: :: If A hasActiveMaterial B → A hasPart B and B is a Material. This consistency allows generic SPARQL queries for `hasPart` or `Material` to still return domain-specific relations. Best Practices -------------- - Use **multiple inheritance** to express both chemical identity and physical form. - Attach properties (e.g., `Density`, `ElectricalConductivity`) using `hasProperty`. - Use **domain-specific part relations** (`hasActiveMaterial`, `hasBinder`, etc.) whenever possible. - When referencing datasheet or literature values, classify the property as a `ConventionalProperty`. - Reuse material nodes rather than duplicating them — this improves linking and consistency across datasets. More Examples -------------- Detailed notebooks are available for common electrochemical materials: .. grid:: .. grid-item-card:: :link: ../../examples/materials/example_cobalt_oxide.ipynb :octicon:`rocket;1em;sd-text-info` Cobalt Oxide ^^^^^^^^^^^ An active material that is common in energy devices .. grid-item-card:: :link: ../../examples/materials/example_gold.ipynb :octicon:`rocket;1em;sd-text-info` Gold ^^^^^^^^^^^ An active material that is common in energy devices .. grid-item-card:: :link: ../../examples/materials/example_iridium_oxide.ipynb :octicon:`rocket;1em;sd-text-info` Iridium Oxide ^^^^^^^^^^^ An active material that is common in energy devices .. grid:: .. grid-item-card:: :link: ../../examples/materials/example_manganese_dioxide.ipynb :octicon:`rocket;1em;sd-text-info` Manganese Dioxide ^^^^^^^^^^^ An active material that is common in energy devices .. grid-item-card:: :link: ../../examples/materials/example_nickel_oxyhydroxide.ipynb :octicon:`rocket;1em;sd-text-info` Nickel Oxyhydroxide ^^^^^^^^^^^ An active material that is common in energy devices .. grid-item-card:: :link: ../../examples/materials/example_nickel.ipynb :octicon:`rocket;1em;sd-text-info` Nickel ^^^^^^^^^^^ An active material that is common in energy devices .. grid:: .. grid-item-card:: :link: ../../examples/materials/example_platinum.ipynb :octicon:`rocket;1em;sd-text-info` Platinum ^^^^^^^^^^^ An active material that is common in energy devices .. grid-item-card:: :link: ../../examples/materials/example_ruthenium_oxide.ipynb :octicon:`rocket;1em;sd-text-info` Ruthenium Oxide ^^^^^^^^^^^ An active material that is common in energy devices .. grid-item-card:: :link: ../../examples/materials/example_silver_oxide.ipynb :octicon:`rocket;1em;sd-text-info` Silver Oxide ^^^^^^^^^^^ An active material that is common in energy devices .. grid:: .. grid-item-card:: :link: ../../examples/materials/example_silver.ipynb :octicon:`rocket;1em;sd-text-info` Silver ^^^^^^^^^^^ An active material that is common in energy devices .. grid-item-card:: :link: ../../examples/materials/example_titanium_dioxide.ipynb :octicon:`rocket;1em;sd-text-info` Titanium Dioxide ^^^^^^^^^^^ An active material that is common in energy devices .. grid-item-card:: :link: ../../examples/materials/example_zinc_oxide.ipynb :octicon:`rocket;1em;sd-text-info` Zinc Oxide ^^^^^^^^^^^ An active material that is common in energy devices .. grid:: .. grid-item-card:: :link: ../../examples/materials/example_zinc.ipynb :octicon:`rocket;1em;sd-text-info` Zinc ^^^^^^^^^^^ An active material that is common in energy devices