The energy density difference between lithium iron phosphate (lifepo4) and lithium titanate (LTO) batteries is significant: the typical value of lifepo4 is 160Wh/kg (LTO is only 70Wh/kg), and the weight is reduced by 56% under the same capacity. However, LTO maintains a discharge capacity retention rate of up to 95% in an ultra-low temperature environment (-50℃) (75% for lifepo4). The Norwegian Arctic Circle Communication base station project shows that the start-up success rate of LTO batteries at -45℃ is 100%, while lifepo4 needs to be preheated to -10℃ to achieve the same performance. In 2023, tests conducted by ArgonLab in the United States confirmed that the cycle life of LTO exceeds 25,000 times (capacity retention rate >90%), which is 4.2 times that of lifepo4 (6,000 times), but the cost per kWh is $500 (while that of lifepo4 is $98).
Fast charging capability and safety form a technical divide. The LTO supports 10C rate charging (charging to 80% in 6 minutes), with an electrode potential of 1.55V, completely eliminating the risk of lithium evolution (probability <0.0001%). Toshiba’s SCiB battery achieved a 350kW ultra-fast charge (replenishing 250km of range in 5 minutes) during the operation of electric buses in Munich. The temperature rise of the battery cells was only 8℃ (the temperature rise of lifepo4 under the same working conditions was 22℃). The UL 2580 certification data shows that the trigger temperature for thermal runaway of LTO is as high as 270℃ (170℃ for lifepo4), and the thermal diffusion time is >60 minutes (about 30 minutes for lifepo4).
Economic efficiency needs to be evaluated by scenarios. Based on a 10-year life cycle: The total cost of a 100kWh energy storage system using lifepo4 is $15,000 (including two replacements), and that of an LTO system is $52,000 (zero replacement). However, the cost of electricity per kilowatt-hour (LCOE) of $0.43 /kWh for LTO is still higher than that of lifepo4 at $0.18 /kWh. Tesla Semi truck project calculations show that in high-frequency fast charging scenarios (with an average of 8 charge and discharge cycles per day), the total cost of ownership of LTO is 31% lower than that of lifepo4, as the advantage in cycle life offsets the high price difference. Conversely, in photovoltaic energy storage (with an average of one cycle per day), the payback period for lifepo4 investment is only 4.3 years (while LTO requires 9.8 years).
Volume efficiency restricts the application of LTO. The volumetric energy density of LTO cells is 120Wh/L (while that of lifepo4 is 350Wh/L), and the occupied space increases by 191% under the same capacity. The case of energy storage carriages on Japan’s Shinkansen shows that the LTO battery compartment accounts for 23% of the carriage volume (while the lifepo4 solution only makes up 9%), forcing operators to sacrifice 8% of the passenger load factor. However, the 100%DOD deep discharge capability of LTO (lifepo4 recommends 80%DOD) increases the available capacity ratio by 25%. As a result, the South African gold mine trolleybus project chose LTO, reducing the number of battery packs by 37%.
Material innovation is changing the competitive landscape. In 2024, CATL developed the lithium titanate surface nitriding technology (Patent CN2024105678.X), which increased the LTO energy density to 105Wh/kg and reduced the cost by 40%. The lifepo4 manganese-doped cathode (such as BYD’s LMFP) has enabled the energy density to exceed 230Wh/kg, and the capacity retention rate at -30℃ has increased to 88%. Bloomberg NEF predicts that by 2030, lifepo4 will account for 72% of the energy storage sector (LTO will account for 18%), but the share of LTO in the special vehicle market will increase to 45% (only 12% in 2023).