AtomGrid · Rosetta v0.1

HC Li-Cu Half-Cell Cycling Data Standard A machine-readable JSON Schema for lithium–copper half-cell (HC) galvanostatic cycling experiments, with a browser validator and GitHub Pages frontend.

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Terminology

⚠️ HC = Half-Cell (Li-Cu configuration) — never Hard Carbon in this schema.

Abbreviation	Meaning
HC	Half-Cell (Li metal anode vs Cu current collector)
AF-LMB	Anode-Free Lithium Metal Battery
CuCC	Copper Current Collector
CE	Coulombic Efficiency (Q_discharge / Q_charge)

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Schema Fields

metadata (required)

Field	Type	Required	Description
experiment_id	string	✅	Unique ID, pattern [A-Za-z0-9_\-]+
date	string (ISO 8601)	✅	Experiment start date YYYY-MM-DD
cell_type	const "HC_Li_Cu"	✅	Fixed identifier
operator	string	—	Researcher name/ID
electrolyte.name	string	✅*	Formulation, e.g. "1M LiTFSI in DOL:DME"
electrolyte.concentration_M	number	—	Salt concentration (mol/L)
electrolyte.solvent	string	—	Solvent system
electrolyte.additive	string	—	Additive
current_collector	const "Cu"	—	Fixed value
capacity_mAh_cm2	number	—	Areal capacity target (mAh/cm²)
area_cm2	number	—	Electrode area (cm²)
current_density_mA_cm2	number	—	Current density (mA/cm²)
temperature_C	number	—	Temperature (°C)

*required when electrolyte object is present

cycles[] (required, minItems: 1)

Field	Type	Required	Description
cycle_number	integer ≥ 1	✅	Sequential cycle index
CE	number [0, 1]	✅	Coulombic efficiency
capacity_charge_mAh_cm2	number ≥ 0	✅	Li plating capacity (mAh/cm²)
capacity_discharge_mAh_cm2	number ≥ 0	✅	Li stripping capacity (mAh/cm²)
voltage_plateau_V	number	—	Stripping plateau vs Li/Li⁺ (V)
timestamp	string (ISO 8601)	—	Cycle completion datetime
overpotential_mV	number	—	Nucleation overpotential (mV)

characterization (optional)

Field	Type	Description
EIS.frequency_Hz	number[]	Frequency sweep (Hz)
EIS.Z_real	number[]	Impedance real part (Ω)
EIS.Z_imag	number[]	Impedance imaginary part (Ω)
EIS.cycle_after	integer	Cycle index for EIS collection
dQ_dV.voltage	number[]	Voltage array (V)
dQ_dV.dQdV	number[]	Differential capacity (mAh/V)
dQ_dV.cycle_number	integer	Source cycle

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Usage

Validate a data file (CLI)

pip install jsonschema
python validator/validate.py schema/example_hc_data.json

Output:

PASS  example_hc_data.json
      experiment_id : HC-2026-001
      cycles        : 9

Validate online

Open the GitHub Pages site → Validator tab → drop your JSON file.

Minimal valid document

{
  "metadata": {
    "experiment_id": "HC-2026-001",
    "date": "2026-05-01",
    "cell_type": "HC_Li_Cu"
  },
  "cycles": [
    {
      "cycle_number": 1,
      "CE": 0.921,
      "capacity_charge_mAh_cm2": 1.002,
      "capacity_discharge_mAh_cm2": 0.923
    }
  ]
}

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Repository Structure

AtomGrid/
├── schema/
│   ├── rosetta_v0.1.json        # JSON Schema (Draft 2020-12)
│   └── example_hc_data.json     # Reference dataset (HC-2026-001)
├── validator/
│   └── validate.py              # CLI validator (Python 3.9+)
├── docs/                        # GitHub Pages frontend
│   ├── index.html               # Schema reference + online validator + CE chart
│   └── schema_viewer.html       # Raw schema display
├── .github/
│   └── workflows/
│       └── validate.yml         # CI: validates example data on every push
└── README.md

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Contributing Data

1. Fork this repository.
2. Add your dataset as schema/<experiment_id>.json.
3. Run python validator/validate.py schema/<experiment_id>.json — must PASS.
4. Open a pull request. CI will re-validate automatically.

Naming convention: <cell_type>-<YYYY>-<NNN>.json, e.g. HC_Li_Cu-2026-002.json.

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Roadmap

Version	Scope
v0.1	HC Li-Cu half-cell cycling (this release)
v0.2	Full-cell schema (cathode + anode)
v0.3	DEIS time-series extension
v0.4	Multi-experiment batch container

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License

MIT © AtomRearch · Zhengqian Jin (Ezra)