The Japan Maritime Self-Defense Force (JMSDF) inducted its first Li-ion battery powered Soryu-class diesel-electric attack submarine in Kobe in Hyogo Prefecture on March 5, 2020.

This is the 11th Soryu-class boat to be commissioned by the JMSDF. This class of submarines are Japan’s first to be fitted with air-independent propulsion (AIP) systems that enable them to remain fully submerged for longer periods of time. These submarines are said to be the world’s largest conventionally powered boats. They are an improved version of Japanese Oyashio-class submarines.

The JS Oryu (SS-511) joins the JMSDF’s Submarine Flotilla 1, based in Kure. It is the first-in-class boat to feature lithium-ion batteries, Naval News reported.

In November 2019, Kawasaki launched the 84-meter long "Toryu" that has a displacement of 2,950 tonnes. It is powered by two Kawasaki 12V 25/25 SB-type diesel engines. The boat is the second in the class to be fitted with lithium-ion batteries to store more power than older Soryu-class submarines. The first boat to pack this feature, JS Oryu, was launched by Mitsubishi Heavy Industries in October 2018.