Saft, a subsidiary of TotalEnergies, is supplying its lithium titanate oxide (LTO) traction batteries to Siemens Mobility to power seven next generation Mireo Plus H hydrogen trains operating in Germany.
The lithium-ion (Li-ion) batteries form a hybrid power system with fuel cells to provide a smart alternative to diesel multiple units (DMUs). This enables the Mireo Plus H trains to offer emission-free autonomous operation on long-distance routes without an overhead supply.
The batteries and fuel cells on the Mireo Plus H trains are controlled so that hydrogen is the primary power source. The batteries are mainly employed during acceleration to compensate for the power limitations of the fuel cells, and during braking to recover kinetic energy. When the train is cruising the batteries perform load leveling to enable the fuel cells to operate with maximum efficiency. A Mireo Plus H train is equipped with two LTO batteries—one for each two-car trainset.
LTO is a key solution added to Saft’s growing portfolio of lithium-ion (Li-ion) chemistries. It offers 10 times the cycle life of other technologies, a high level of safety due to its stable electrochemistry, and the high-performance charge and discharge capability, 10 times superior to traditional Li-ion batteries, essential for traction applications.
Saft is one of the few companies to develop its own chemistries, enabling it to tailor its products to the specific needs of each of its customers. The development of LTO batteries for Siemens Mobility drew on the strength of Saft’s global presence. The LTO technology was developed in the Saft research center in Bordeaux and is assembled in Nersac, France. Deliveries of the LTO batteries to Siemens Mobility started in summer 2024.