GMG Reports 1,000 Six-minute Charge Cycles For Its Graphene G CELLS

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Graphene Manufacturing Group says its 1.5 Ah G CELL pouch cells completed 1,000 charge-and-discharge cycles, with each charge and discharge taking six minutes, without a measured performance reduction as of Oct. 7, 2026. The test was conducted by Indiana’s Battery Innovation Center; the results are company-reported test data, not evidence of commercial-scale performance.

Graphene Manufacturing Group says its G CELL pouch cells completed 1,000 six-minute charge-and-discharge cycles without a reported reduction in performance, according to test data dated Oct. 7, 2026. The 1.5 amp-hour cells were built and tested by Indiana’s Battery Innovation Center, providing a new durability result for GMG’s developing graphene aluminum-ion battery technology.

The cells were charged and discharged at a 7 C rate, a rate expressed relative to a cell’s capacity. GMG said the 1,000-cycle count is twice the count in its previous update, which covered cells cycled at 10 C. The new cycle result and the earlier 10 C measurements describe different test conditions and should not be treated as a direct like-for-like comparison.

GMG also reported separate six-minute, 10 C results. One G CELL had a 10% performance reduction after 393 cycles; specific energy reached 58 watt-hours per kilogram, up from 39 Wh/kg in the company’s previous update. GMG reported 94% energy efficiency for the G CELL at that rate, compared with 64% for an LTO cell tested at the same six-minute charge-and-discharge duration.

For that comparison, GMG said the lithium titanate oxide (LTO) cell fell to 80% of its original capacity within 82 cycles when charged and discharged at 10 C. That capacity level is typically treated as a cell’s end of life. These figures come from the reported tests; the supplied material does not describe independent verification or testing in a vehicle or grid-storage system.

Fast Charging Meets Cycle-Life Testing

Repeated fast charging can put pressure on battery durability, so cycle life under short charge times is a relevant measure for technologies proposed for electric vehicles and energy storage. GMG’s reported result adds evidence that its small-format cells can undergo many rapid cycles in laboratory testing. The reported 94% energy efficiency also points to a potential advantage in the tested conditions, since less input energy is lost during charging and discharging.

However, the results do not establish how the cells would perform in larger packs, under varied temperatures, or across the much longer service life expected of commercial products. The reported energy density is also a cell-level figure, not a measure of a complete battery system. The findings are an early technical milestone, rather than proof that the technology is ready for market or will improve EV adoption.

GMG’s Cell Development and Test Setup

GMG describes G CELLS as graphene aluminum-ion cells that use no lithium or rare-earth materials. The company developed, manufactured and supplied the graphene materials from its Brisbane Battery Development Centre. Indiana’s Battery Innovation Center built the 1.5 Ah pouch cells and collected the test data, according to the report.

GMG is developing the technology under a joint development agreement with Rio Tinto. Its prior update included a 10 C test in which a G CELL showed a 10% performance reduction after 393 cycles, as well as a reported specific energy of 39 Wh/kg. The current report adds a 1,000-cycle result at 7 C and updated 10 C measurements; the figures do not all come from the same test condition.

“Energy that isn’t lost as heat is what makes fast charging practical at the system level.”

— Bob Galyen, GMG director and former chief technology officer of CATL

Limits of the Reported Cell Tests

The report does not provide enough detail to assess the full test protocol, including temperature, charging controls, cell-to-cell variation, or how performance was defined for the 1,000-cycle result. It also does not state whether an outside party independently reviewed the data. The 1,000-cycle finding is reported at 7 C, while the LTO comparison and the other G CELL measurements cited above were conducted at 10 C.

It remains unclear how these results will translate to larger-format cells, complete battery packs, cost, manufacturing consistency, or operation in real-world vehicles and storage installations. The source material does not give a commercialization schedule or say when additional results will be released.

Scaling G CELLS Beyond Pouch Tests

GMG says its next work will focus on improving energy density and 10 C cycle life, and on scaling the cells to larger formats. Further data from those efforts would help show whether the laboratory results can be reproduced beyond 1.5 Ah pouch cells and under conditions closer to commercial use.

No timetable for larger-cell testing or product availability was provided in the report. The next meaningful development will be additional, clearly specified test results that allow comparison across cell formats and charge rates.

Key Questions

What did GMG report?

GMG reported that its 1.5 Ah G CELL pouch cells completed 1,000 charge-and-discharge cycles, with charging and discharging taking six minutes, at a 7 C rate. The company said there was no performance reduction as of Oct. 7, 2026.

Who conducted the testing?

Indiana’s Battery Innovation Center built the pouch cells and collected the data. GMG developed and supplied the graphene materials used in the cells.

How did the G CELL compare with the LTO cell?

In a separate six-minute, 10 C test, GMG reported that an LTO cell reached 80% of its original capacity within 82 cycles. A G CELL tested at the same rate showed a 10% performance reduction after 393 cycles. These are company-reported results, and the report does not establish independent verification.

Are G CELLS ready for commercial use?

The reported data do not establish commercial readiness. The tests involved 1.5 Ah pouch cells, and GMG said it still aims to improve energy density and cycle life at 10 C and scale to larger cell formats.

Source: rss