Demonstrated

Results on commercial cells, validated by a national lab.

This is a real cell hiding real lithium plating.
Every other test on the line called it healthy.

Measured Bx field map of INL Cell 14 at 1 kHz — smooth, symmetric contours of a cell in optimal condition
CELL 14 — OPTIMAL
Measured Bx field map of INL Cell 15 at 1 kHz — contour distortion in the lower right marking lithium plating
CELL 15 — PLATING, LOWER RIGHT
Figure 3Measured data — not a simulation. Bx field maps of two 11 Ah commercial cells at 1 kHz, raw from the instrument, from the Idaho National Laboratory validation campaign. Cell 15 carries the signature of lithium plating after only 12 fast-charge cycles (up to 3C) — with no voltage or temperature anomaly to be found. 56 × 50 mm region; both maps on a common scale.

One result is a demonstration.
Six is a track record.

Across four years, four defect classes, and partners from LG to a national lab — every detection below is tied to a specific commercial cell and program milestone.

01

Torn-tab detection

Detected submillimeter torn tabs in 59 Ah GM Bolt-type cells for LG during Phase I — the exact defect class behind the $2B recall.

02

Lithium-plating detection, independently validated

Detected plating in 11 Ah commercial Kokam cells, validated with Idaho National Laboratory — to our knowledge a first for any non-invasive sensing method. The measured data is Figure 3, above.

03

Hidden weld-defect localization

Localized a hidden weld defect in 30 Ah commercial pouch cells returned from the field — a cell that had passed conventional QC. (2025)

04

Format- and chemistry-agnostic in practice

Demonstrated across NMC pouch and LFP prismatic formats, from 200 mAh to 100 Ah class cells — four distinct defect groups to date. (2025)

05

Phase IIB Go/No-Go: passed

EMIS output correlated with fast-charge cycle number in 9 of 10 cells (each ≥10 Ah) — the DOE-defined success threshold for autonomous, machine-readable detection. (2025)

06

Instrument-grade precision, commodity cost

0.02% impedance accuracy (0.005 mΩ at 2.5 mΩ) on in-house electronics, while hardware cost fell $50k → $4k → ~$1k across program phases.

Built & validated with
CaltechOrigin of the technology & patents
Idaho National LaboratoryIndependent plating validation
U.S. Department of EnergyPhase I / II / IIB program support
NRELPhysics simulation & ML-training partner
Berkeley National LaboratoryFailure-statistics & ML analysis partner
LG Energy SolutionProgram partner & prospective customer

Send us your cells. We send back the maps — your defects, your data, in two weeks.

Start a validation project

The signature atlas

What the lab measured once, EMIS reads in every defect class.

The same physics that resolved the INL plating signature generalizes: a torn tab pulls the field toward a corner, plating blooms as a hot-spot, a short collapses the contours to a point. Each break in symmetry is distinct — and machine-classifiable.

Healthy referencebaseline
Torn tabcorner
Lithium platinghot-spot
Internal shortpoint
Figure 2Signature atlas. Each defect class breaks the field's symmetry in its own way — a torn tab toward a corner, plating as a hot-spot, a short to a point. Distinct signatures are what make the output machine-classifiable. Physics-based, calibrated to measured cells.

The system, not the box

Anyone can build an instrument. We're building the reference.

That measured result is proof of one cell. The deeper advantage is what happens when you measure thousands: every image EMIS captures sharpens a model trained on real, validated commercial-cell signatures — the layer the industry will calibrate against.

Here's how a single measurement compounds into a standard a competitor can't simply buy:

01

Scan

EMIS images a cell's internal current density on the line or the bench — on-prem, your data never leaving the factory.

02

Label

Each signature is tied to a known outcome — torn tab, plating, short, weld defect — validated against teardown and national-lab ground truth.

03

Sharpen

The model that turns a 2D field into a machine-readable verdict improves — better thresholds, fewer false positives, broader cell coverage.

04

Compound

Detection improves for the whole field, which pulls more cells through EMIS. The reference standard for "is this cell electrochemically sound" accrues to whoever measured the most cells first.

For investors: the instrument is the wedge; the labeled-signature dataset and the on-prem inference standard are the moat. Earlier patent priority (2013) plus the first large corpus of measured commercial-cell signatures is a position a better-funded fast-follower cannot simply buy.


The full case · the problem

A single point of scrap costs a gigafactory roughly €10M a year.

The battery industry still lacks the inline QC maturity of semiconductors. A chip fab inspects every wafer in real time; most cell lines rely on delayed testing and days of aging — and still miss the defects that matter most.

The problem, measured
15–30%
Scrap rate, early years
Still ~10% after five years. Fraunhofer FFB / RWTH Aachen, 2025
€30k
Per day, per scrap point
Each point of scrap at full capacity — about €10M a year. Fraunhofer FFB, 2025
10–15%
Lost to late detection
Cells scrapped or reworked after delayed testing. Nature Comms / Attia et al., 2025
The opportunity, measured
$10/kWh today $5/kWh with EMIS = ~$25Mrecovered per year, 5 GWh line

Large-cell scrap runs double small-cell cost because manufacturers raise thresholds to cover what they can't measure. EMIS halves it — against a software fee comparable to existing QC.


The full case · the blind spot

Every fast tool on the line reads one of two signals. EMIS reads a third.

Each waits for damage to surface as voltage, gas, or geometry. EMIS images the current density itself — where the recall-class defects appear first.

Self-discharge Ultrasound X-ray / CT Eddy current Parthian EMIS
Signal measured Self-discharge current Acoustic interfaces X-ray attenuation (geometry) Surface-induced currents Internal current density
Images electrochemical function Bulk average only No No — structure only No Yes — spatially resolved
Catches torn / misaligned tabs No — until leaking Limited If geometric Surface only Yes — demonstrated
Catches lithium plating No Only after drying/gassing No No Yes — INL-validated
Catches resistive weld defects No No Geometry, not resistance Limited Yes — demonstrated
Needs cell relaxation / aging Yes Built + wetted first No No No
Works before electrolyte injection No No Yes Shallow layers Yes
Output Pass / fail 2D map / scalar 3D geometry Scalar 2D map today → scalar (roadmap)
Earlier

Flags defects on a dry electrode stack — before electrolyte injection, with no relaxation period.

Broader

Catches the recall-class faults the fast tools can't see — torn tabs, shorts, and lithium plating, validated.

Frictionless

Rides the existing ACIR station — no added line time, a <1 mm sensor plate, ML on-prem.


How EMIS works

An MRI for the inside of a cell — no contact, no opening it up.

A cell's own current makes a magnetic field. Read that field from just above the surface, reconstruct the current inside, and a defect reveals itself as broken symmetry. Here's the idea on a chalkboard.

So — how do you see inside a battery without opening it up? ① The current doesn't flow evenly. + ↑ here's our troublemaker ② Moving charge makes a magnetic field. I it curlsaround ③ We read it from outside. tiny magnetometers — they never touch the cell the field, as measured Now here's the catch. Going forward — current to field — is just textbook physics: B(r) = (μ₀/4π) ∫ J(r′) × (r−r′)/|r−r′|³ dV′ …the Biot–Savart law. Nothing new. But we want to go backward — field to current. And that's slippery, because many different interior currents can make the very same field outside. So you can't just invert it. You teach a model what real defects look like — and let it choose. — the inverse problem
Figure 1The forward problem is physics; the inverse problem is the hard part. Current inside the cell produces a magnetic field by the Biot–Savart law — that direction is exact. Recovering the interior current from the field measured outside is a classic ill-posed inverse problem (the same mathematical class as magnetoencephalography): many interior currents fit the same exterior field. EMIS resolves it with a learned operator trained against national-lab-validated cells, rather than inverting analytically.

Available now · Model EMIS08S01

The Inhomogeneity Mapper, for research labs.

Teams studying lithium plating and fast-charge cell design get an imaging tool that sees what nothing else can — today. Up to 1,000,000× more data points per cell than a single ACIR reading.

The instrument

A benchtop gantry images a cell's internal current density — non-contact, no teardown — and returns a machine-readable defect map. Chemistry-, size-, and format-agnostic, 200 mAh to 100 Ah. From US$ 9,975 / 6-month rental.

Step one · no commitment

Get the datasheet

Full EMIS08S01 specifications, measurement modes, and channel architecture — everything your engineers need to evaluate fit.

FreePDF, by email
Request datasheet
Step two · see your own cells

Run a validation

Send us cells — healthy, suspect, or returned from the field. We image them and send back the current-density maps with a defect read. Your data, in about two weeks.

Scoped per projectNDA-backed; your data stays yours
Start a validation
Step three · bring it in-house

Rent the instrument

The EMIS08S01 on your bench. License, EIS hardware, and the 8-channel mapper included; XYZ gantry optional.

US$ 9,9756-month rental, then US$ 999/mo × 18
Reserve a unit

Pricing shown for the research configuration. Manufacturing / inline integration is scoped directly — talk to us.


The people

Invented by its founders. Vetted by the people who built the field.

Founder · CEO

Farshid Roumi, PhD

Caltech PhD. Inventor on 23+ patents. Recognized by the U.S. government as an Individual with Extraordinary Ability in Science.

Full bio

Former senior research scientist at Caltech, where he founded and led an advanced energy-storage lab. Recognized as an Individual with Extraordinary Ability in Science and Engineering (2012); selected for the National Academy of Engineering's Frontiers of Engineering (2023).

Co-founder · Vice President · Principal Investigator

Michelle Mahshid Roumi, PhD

ML and signal processing for faint signals in noise. Her neutrino-detector hardware has run autonomously in Antarctica since 2013.

Full bio

Developed an FPGA image-processing engine up to 4× faster than the reported state of the art. Former Caltech postdoctoral scholar; co-inventor of the EMIS patent family; PI of this program since Phase I.

Rachid Yazami, PhDAdvisory board

Co-inventor of the graphite anode in every lithium-ion battery; Draper Prize laureate; co-inventor on 140+ battery patents; former president of the International Battery Association.

Mehdi Hatamian, PhDElectrical engineering advisor

Member of the National Academy of Engineering for co-inventing the communications ICs in our cell phones; former Senior Vice President at Broadcom.

Puon Penn, MBAChief Strategy Officer

Former Executive Vice President at Wells Fargo, where he led the bank's venture investing business and founded its Global CleanTech Group.

Brian Dillard, M.S.Adviser

Former Johnson Controls executive director for systems electronics and battery management systems; senior roles across EV battery manufacturing and integration.


Get in touch

Tell us about your cells.

Request a validation — or write directly to froumi@parthiannrg.com

We respond within two business days. Your cells and your data stay yours — NDA-backed.

Technology foundation

Invented at Caltech (2013) and exclusively licensed to Parthian, with NAE-member advisors and a published image- and signal-processing track record behind the machine learning.

A substantial issued-and-pending patent family spans US, EU, JP, KR, and CN.

Who we work with

  • 01 Gigafactory quality-control & process engineers
  • 02 National-lab & university battery researchers
  • 03 Strategic partners & investors