This NVP dataset is most useful as a first-cycle data-quality example. The S07 trace reports 106.75 mAh/g and 98.75% first-cycle coulombic efficiency at 8.0 mg/cm2 in a sodium-metal 2320 coin cell, which is a credible half-cell screening result. Two other traces on the same slide report coulombic efficiency above 100%, so they should be treated as abnormal screening data until the raw charge-discharge file, capacity integration, and formation sequence are checked. The publishable point is therefore not the highest capacity value; it is the need to separate valid NVP screening data from curves that require verification.
What the S07 NVP Result Shows
S07 shows a stable plateau-dominant profile in the 2.0-3.8 V window, with 106.75 mAh/g reported capacity and 98.75% first-cycle efficiency. For a sodium vanadium phosphate cathode, that combination is useful because a high but still sub-100% first-cycle efficiency can be used in preliminary sodium-inventory planning. The curve supports an NVP half-cell baseline under the stated loading and rate, but it does not establish cycle life, rate behavior, or full-cell performance.
Test Conditions and Data Source
The following conditions are transcribed from the supplied NVP charge-discharge chart. The figure includes S07, S02, and S03 panels. S07 is treated as the technically usable result because its first-cycle efficiency is below 100%; S02 and S03 are retained in the table as data-quality flags rather than performance claims.
| Parameter | Reported condition or result |
|---|---|
| Cell format | 2320 coin cell |
| Electrode pair | NVP cathode versus sodium metal |
| Electrolyte | 1 M NaPF6 in DEGDME |
| Voltage range | 2.0-3.8 V |
| Charge / discharge rate | 0.1C / 0.1C |
| Test temperature | 25 +/- 1 C |
| S07 | 8.0 mg/cm2; 106.75 mAh/g; 98.75% first-cycle efficiency; technically usable trace |
| S02 | 10 mg/cm2; 108.75 mAh/g; 104.98% first-cycle efficiency; requires data-quality review |
| S03 | Dry electrode; 20 mg/cm2; 108.46 mAh/g; 102.51% first-cycle efficiency; requires data-quality review |
| Data source | NVP charge-discharge performance chart supplied for this article |
Why Above-100% First-Cycle Efficiency Needs Review
A first-cycle coulombic efficiency above 100% in a half-cell chart is usually a signal to inspect the measurement rather than a reason to advertise superior performance. Possible causes include capacity-integration direction, charge/discharge labeling, sodium-metal side reactions, rest-step treatment, data export settings, or mismatch between the plotted cycle and the reported efficiency. In this slide, S02 reports 104.98% and S03 reports 102.51%, so both should be excluded from public performance claims until the raw file is reconciled.
For repeat screening, researchers should keep the same cutoff window, formation protocol, electrolyte volume, separator, sodium source, and electrode geometry. The NVP electrode sheet at 20 mg/cm2 is relevant to the dry S03-style loading question, while a 30 mg/cm2 NVP cathode sheet is a separate high-loading follow-up condition that should be tested in its own matrix. Powder-level comparison can start from NVP sodium vanadium phosphate cathode powder before moving into coated electrodes.
What This Dataset Supports – and What It Does Not
Supported by the reported chart: an S07 NVP sodium-cathode half-cell baseline at 8.0 mg/cm2, 2.0-3.8 V, 0.1C/0.1C, and 25 +/- 1 C; a reported S07 capacity of 106.75 mAh/g; and a reported S07 first-cycle efficiency of 98.75%.
Not supported without review: using S02 or S03 as final performance evidence, claiming that dry processing has been validated by S03, or ranking NVP variants from the three traces alone. The abnormal >100% first-cycle efficiency values must be resolved before those curves can be used for SEO, product, or customer-facing claims.
Next Validation Steps for NVP Qualification
The next experiment should repeat S07 across multiple cells, then rerun S02 and S03 with audited raw data, matched electrode area, confirmed mass loading, and fixed integration rules. Use battery test equipment and instruments that can preserve the same current, cutoff, rest, and export protocol across the comparison set. The wider Battery Research hub provides the surrounding workflow for moving from curve review to electrode and full-cell validation.
Once a repeatable NVP cathode condition is confirmed, a later full-cell experiment can pair it with a measured hard-carbon anode and an explicit N/P target. An NVP hard-carbon 1Ah dry pouch cell shows the type of paired-electrode format that can follow after coin-cell data quality is under control. It is a validation route, not evidence that the S07 half-cell curve already represents pouch-cell performance.
Data Scope
This article interprets the supplied NVP first-cycle voltage-capacity chart only. It accepts S07 as the usable screening trace and treats S02/S03 as data-quality review items because their reported first-cycle efficiencies exceed 100%. It does not add unreported cycle-life, rate, impedance, density, replicate statistics, dry-process validation, or full-cell data. Researchers requiring comparable NVP testing should specify the target loading, process route, voltage window, electrolyte, cell format, raw-data export rules, and validation objective when contacting ATOMFAIR at inquiry@atomfair.com.