The Japan Maritime Self-Defense Force on Thursday welcomed into service its first submarine using lithium-ion batteries with the commissioning of the 11th Soryu-class boat.
In a ceremony held at the Mitsubishi Heavy Industries shipyard in the city of Kobe, officials welcomed the diesel-electric attack submarine Ouryu into service, where it will be assigned to the 1st Submarine Flotilla in the nearby port of Kure.
The Ouryu is the sixth Soryu-class boat to be built by MHI, with Kawasaki Heavy Industries having built five more and building the 12th and last such submarine ordered by Japan. The Ouryu was launched in October 2018.
Both Ouryu and the last boat in its class, which will be christened the Toryu, will be slightly different from the earlier boats in the class, as they’ll use lithium-ion batteries manufactured by GS Yuasa in lieu of Stirling-cycle engines that recharge traditional lead-acid batteries for submerged operations.
Speaking during a 2017 presentation in Singapore, former head of the Japan Maritime Self-Defense Force’s submarine fleet Vice Adm. Masao Kobayashi said the batteries used in the Ouryu and Toryu are lithium nickel cobalt aluminum oxide, or NCA, batteries. He said the technology requires less maintenance and is capable of longer endurance at high speeds while submerged compared to lead-acid batteries.
