Updated November 5, 2026 What changed after Gelion's 750-cycle TDK result Gelion's sulfur-cathode story now includes independent U.S. laboratory testing and a co-funded automotive evaluation. Those developments broaden the evidence beyond the March TDK result reported below. They do not establish that a sulfur battery is ready to replace the LFP systems being ordered for grid projects. On October 19, Gelion reported preliminary results from the National Laboratory of the Rockies under the cooperation agreement announced in June. The laboratory fabricated electrodes from Gelion's Nano-Encapsulated Sulfur cathode active material and assembled lithium-metal-anode coin cells. According to the company, the laboratory reproduced key electrochemical behaviour observed internally, including voltage profile, sulfur utilisation and capacity fade. 92% at a higher rate is not a cycle-life guarantee The headline result was retention of 92% of reference capacity when the cycling rate increased from 0.1C to 2C, a twenty-fold increase. This compares capacity available at two operating rates. It does not mean 92% capacity remained after a specified number of years or thousands of cycles. Nor is it the same cell architecture as the graphite-anode TDK work: the U.S. laboratory test used Gelion's baseline lithium-metal platform. Gelion also cited QinetiQ testing of independently built lithium-sulfur pouch cells, including sustained 3C operation and 6C pulses in drone-representative duty cycles. The company reported closely aligned voltage profiles over 50 cycles incorporating take-off, cruise and landing phases. A 6C rate corresponds mathematically to a ten-minute full discharge if maintained, but a pulse result is not proof of a ten-minute full recharge or an automotive pack specification. An automotive partner joins the qualification work On October 13, Gelion announced a co-funded proof-of-concept agreement with an unnamed top-five global automotive manufacturer. The programme will evaluate cells combining NES cathode material with a graphitic anode under EV-relevant conditions. The manufacturer contributes engineering expertise, testing facilities and part of the funding, while Gelion conducts complementary tests to correlate results. That agreement follows an October 6 material-testing agreement with a top-15 automotive manufacturer. These are evaluation programmes, not disclosed production orders. The top-five partner's identity, commercial volumes and a production start date were not supplied in the announcement. Potential compatibility with existing manufacturing equipment still has to be demonstrated through qualification and scale-up. The financial and manufacturing checkpoints Gelion's October 21 results for the year ended June 30 reported total income of £2.5 million, versus £2.7 million a year earlier, and an adjusted EBITDA loss of £4.4 million, compared with £4.1 million. The company said income primarily comprised government grants and research tax incentives or credits. These figures describe a development business, not evidence of large-scale sulfur-cell sales. The results also identified a £2.0 million funded development and scale-up agreement with Mitsui Kinzoku covering potential automotive, stationary-storage, consumer-electronics, aerospace and defence applications. For the U.S. laboratory programme, the next stage includes larger-format pouch-cell prototypes and further validation. The evidence to watch is performance at practical cell size, manufacturing yield, safety testing and customer qualification, rather than treating a single laboratory metric as a finished product. The Canadian Solar and Drax section below remains a record of the March 31 contract announcement. Its 420 MWh total and installation timetable are the figures announced then, not a fresh confirmation that either project has entered service. Keeping that procurement story separate from experimental chemistry avoids confusing a commercial LFP order with sulfur-battery readiness. Primary sources: U.S. laboratory results, October 19 ; automotive proof-of-concept agreement, October 13 ; FY2026 results, October 21 . Two announcements landed on Tuesday, March 31 that capture where the battery industry is heading from two very different directions: a small Australian chemistry startup hit a milestone that puts it one step closer to replacing the cobalt and nickel in today's lithium-ion batteries with cheap, abundant sulfur, while Canadian Solar's storage arm signed the largest UK grid storage deal of the year so far. Neither is a finished product. Both are exactly the kind of progress the industry needs. Gelion and TDK Hit 750 Cycles With Sulfur Cathodes on Standard Graphite Anodes Gelion, a UK-listed company that grew out of research at the University of Sydney, disclosed on March 31 that testing with Japanese electronics giant TDK Corporation has produced results strong enough to expand their collaboration into commercially relevant cell formats. The headline figure: over 750 cycles at a 1C charge/discharge rate with 100% depth of discharge, using graphitic anodes, which are the same carbon-based negative electrodes found in virtually every lithium-ion battery made today. That last detail matters more than it might seem. Lithium-sulfur batteries have been a promising chemistry for decades, but they have historically required lithium-metal anodes to function well. Lithium metal is tricky to handle at scale, prone to growing needle-like dendrites that can short-circuit a cell, and not compatible with the existing gigafactory infrastructure that the battery industry has spent billions building out. Gelion's approach sidesteps the problem: its Nano-Encapsulated Sulfur (NES) cathode technology is designed to serve as the sole reservoir of lithium in a full cell, letting a standard graphite anode do what it already does in a conventional lithium-ion pack. Gelion's NES cathode cells are now being tested in standard pouch cell formats at TDK's Nagano, Japan facility. The partnership between Gelion and TDK started in April 2025 as a materials testing agreement. By October 2025, the results were good enough that TDK agreed to a multi-year full collaboration, with production qualification targeted within 12 months of that signing. The March 31 update expands the scope again, adding silicon-dominant anodes to the testing roadmap alongside graphite, and confirming that Gelion has developed working protocols to lithiate the NES cathode at scale. Lithiation, the process of loading lithium into the sulfur cathode before assembly, has historically been one of the trickiest process steps for lithium-sulfur cells aiming at industrial production. Why Sulfur Could Be a Supply Chain Game-Changer In a lithium-sulfur cell, sulfur serves as the cathode active material, replacing the cobalt, nickel, and manganese used in NMC and NCA chemistries. Battery cathode chemistry is the part of the supply chain that keeps energy security officials up at night. NMC cells require nickel, manganese, and cobalt. NCA cells require nickel and cobalt. Cobalt in particular comes overwhelmingly from the Democratic Republic of Congo, a source with well-documented human rights concerns and geopolitical risk. Even LFP, which has no cobalt, relies on lithium phosphate processing concentrated in China. Sulfur is an entirely different situation. It is one of the most abundant elements in Earth's crust, and a byproduct of oil refining and natural gas processing in industrial quantities. In some scenarios, sulfur cathodes could draw on material that would otherwise be disposed of as waste. Gelion's NES platform also carries no strategic mineral supply chain dependencies beyond lithium itself, which it manages by incorporating all the needed lithium into the cathode rather than requiring a dedicated lithium-metal anode. The potential energy density advantage is real too. Theoretical lithium-sulfur energy densities can exceed 500 Wh/