The safety of high-power pure battery power, the increase of energy power density, and the high one-time cost will be difficult problems for the promotion and application of pure battery power in ships. It is necessary to strengthen technical research and development, conduct full testing and verification to ensure safe and reliable applications and economic .
Because electric ships need to carry a large number of batteries, the discharge rate, cycle and cost of the batteries are relatively high. Especially in terms of safety, it puts forward severe requirements on battery companies.
According to foreign media reports, the lithium titanate battery system produced by Swedish Echandia Shipping Company has been acquired by DNV GL, one of the world's leading classification societies ) Safety certification issued.
Echandia said its E-LTO energy storage system uses Toshiba's lithium titanate batteries. In order to obtain certification, Echandia conducted a series of tests including thermal runaway, internal / external short circuit, forced discharge, EMC, environmental test, software function test and battery system performance, etc., to verify the safety and reliability of the lithium titanate battery system.
Compared to other types of batteries, Echandia says that E-LTO provides excellent passive precautions to prevent such potentially catastrophic transmission.
Previously, DNV GL released a new report on the safety of marine batteries, which assesses the risks of explosion and fire in marine battery installations and the effectiveness of fire suppression systems in the event of battery fires.
The report provides new recommendations for ventilation systems based on a newly created model that determines the appropriate size and type of ventilation system based on the ship's battery installation. Early fire and gas detection is also important, which means that the gas sensor should be placed as close as possible to the battery.
In addition, the report also pointed out that compared to NMC batteries, lithium iron phosphate batteries are often more difficult to be forced into a thermal runaway state. For NMC batteries, the temperature rise rate is also low.
This shows that lithium iron phosphate batteries and ternary batteries have certain safety risks when they are applied on ships, and the safety performance of lithium titanate batteries that do not fire may provide a new power option for electric ships.
It is understood that Echandia's heavy-duty LTO battery system is used in the marine and railway markets. The company's lithium titanate battery system is designed to be used continuously for 10 years or more, to ensure heavy operation without affecting safety or performance, and has strong charging performance and high power charging and discharging capabilities.
In 2019, Toshiba announced that it has developed a new lithium-ion battery that is fast-charging and long-lasting. It is reported that when the battery is used in small electric vehicles (EV), it can travel 320 kilometers in 6 minutes of charging, which is about three times the past.
On the cycle, even if the battery is repeatedly charged and discharged 5000 times, it can still maintain more than 90% of the battery capacity. In addition, fast charging can be achieved in a low temperature environment of minus 10 ° C.
In terms of industrialization, Toshiba expects mass production in the first half of the 2020s.
Gaogong Lithium learned that Toshiba's battery technology was developed based on its previous SCiB system. It uses a lithium-ion battery with titanium-niobium oxide as the anode material and its lithium-ion storage capacity is graphite The anode material is twice the lithium battery.
It is worth noting that Toshiba is not the only company in the industry that currently provides electric marine lithium titanate battery systems.
In addition to Toshiba, Swiss battery system provider Leclanché SA also produces ternary and lithium titanate batteries. The company's lithium battery system designed for European electric ships has also obtained type approval and product certification from DNV-GL.
In China, marine lithium batteries must pass the qualification certification of China Classification Society (CCS) and its authorized agencies, and CCS only recognizes square lithium iron phosphate, which represents companies such as Ningde Times and Everlite Lithium Energy.
As of June 2019, the number of domestic marine lithium-ion battery companies certified by classification societies is relatively small, with 11 certified companies and 25 certified battery products. The market competition is relatively small.
From the perspective of the certified product technology route, it is mainly square, accounting for 76%; from the current actual use of electric boat power batteries, LFP square power batteries with better comprehensive performance in terms of safety, cycle and rate are the mainstream. .
Internationally, hybrid and marine battery suppliers Corvus Energy, German battery manufacturer Akasol AG, and Nidec, Saft Group, Samsung SDI, GS Yuasa and other companies are also actively developing marine lithium battery systems. The emerging marine lithium battery market has gained a foothold.