This groundbreaking test, far exceeding industry standards, validates Hithium's multi-layered safety architecture and sets a new benchmark for the global energy storage industry.
In a significant leap forward for energy storage safety, Hithium announced the full results of its pioneering all open-door large-scale fire test for its ∞Block 5MWh energy storage system. The announcement was made on June 11, 2025, during the 18th SNEC, where Hithium held a product safety technology sharing event themed "Leading the Future, Forged for Safety." The company also received a large-scale fire test certification from the esteemed international testing authority UL Solutions, underscoring the rigorous validation of its system's safety.
The unique aspect of this fire test was its "all open-door" configuration, a deliberate choice to simulate the most extreme conditions possible. The test was initiated by intentionally heating eight battery cells within container A to trigger thermal runaway, leading to cell-to-cell propagation. As the battery's pressure relief vents opened, an ignition system ignited the released gases, allowing for full combustion with the container doors kept wide open. This critical setup ensured a continuous flow of oxygen, maximizing heat exposure to the adjacent containers B, C, and D. The test was further intensified by being conducted under four extreme conditions: all open-door combustion, dual 15 cm extreme spacing between containers, a completely deactivated fire suppression system, and a 100% State of Charge (SOC) for all batteries.
During the peak fire phase, observed at the fourth hour of testing, the fire reached a staggering temperature of 1,372°C. Despite this intense heat, continuous temperature monitoring confirmed that the cell temperatures in all adjacent containers remained significantly below the thermal runaway initiation threshold defined by the UL9540A cell-level test. Specifically, temperatures were recorded at ≤42°C in Container B, ≤80°C in Container C, and ≤70°C in Container D, demonstrating exceptional thermal containment.
The sustained combustion phase saw the open flame extinguished after an impressive 15 hours. Crucially, the initiating container maintained its structural integrity without any deformation or collapse. Most importantly, no combustion or thermal runaway propagation occurred in the three adjacent containers (B, C, and D). These containers only experienced minor surface damage, with their internal battery modules remaining completely unaffected, a testament to Hithium's advanced safety design.
This unparalleled test success is attributed to Hithium's sophisticated multi-layered safety architecture, meticulously designed across the cell, module, and system levels. At the cell level, the integration of heat-resistant anode/cathode materials, functional electrolyte additives, and high-temperature separators significantly raised thermal thresholds. At the module level, the incorporation of low-conductivity insulation and flame-retardant top covers effectively minimized the risk of propagation between cells and modules.
