US media: Japanese AIP submarines switch to lithium batteries, double the endurance

On July 15, the US \"National Interest\" bimonthly website published an article by Caleb Larsen \"Why the Japanese Canglong-class stealth submarine is so powerful\", saying that the Japanese Sea from the Canglong-class submarine uses lithium-ion batteries, which can be used in water at most. It has sailed for two consecutive weeks and adopts AIP propulsion technology, which can greatly reduce the noise of underwater navigation and has strong underwater combat capabilities. The article is excerpted as follows:

The Japan Maritime Self-Defense Force will have a total of 12 Canglong-class submarines. These diesel-electric powered attack submarines (the first boat) were originally enlisted in the Japan Maritime Self-Defense Force in 2009 and have some interesting features.

The first submarine built in Japan to use lithium-ion batteries \"Huanglong\" belongs to the Canglong class. For a long time, the batteries used in diesel-electric submarines are similar to those used to power cars—lead-acid batteries. Compared with earlier lead-acid batteries, lithium-ion batteries are smaller and lighter, but they can produce greater output power. Therefore, lithium-ion batteries have certain advantages in power storage.

The charging speed of lithium-ion batteries is usually faster than that of lead-acid batteries, which reduces the time for submarines to surface-the surface is where the submarine is vulnerable to attack, so the submarine's underwater endurance is greatly improved. Some sources said that switching to lithium-ion batteries can double the submarine's underwater endurance, up to two weeks. If the situation is true, the underwater endurance of the Canglong-class submarine is quite good.

The Canglong-class submarine is also the first submarine in Japan to use \"air propulsion technology\" (AIP). Although this class of submarines are diesel-electric submarines, some of them can convert a noisy diesel engine into a less noisy Stirling engine.

The Stirling engine used by the Canglong-class submarine is modified from a Swedish Stirling engine. This unique engine uses bottled liquid oxygen, which helps the combustion of diesel in the engine. The advantage of this propulsion system is that it is less noisy than traditional diesel engines (it is harder to be detected by enemy anti-submarine sonar, this net note). In addition, its range is estimated to be around 6,100 miles (about 9,800 kilometers).

Although this class of submarine is not equipped with a vertical missile launch tube, it can launch US-made submarine-launched \"Harpoon\" anti-ship missiles through six torpedo tubes arranged in the bow. This missile can fly by skimming the sea to avoid enemy radar detection, and its range can reach 170 miles (approximately 270 kilometers). In addition, these submarines are also equipped with heavy torpedoes and can be deployed with anti-submarine and anti-ship mines.

Both India and Australia have expressed interest in acquiring Japanese submarine technology, if not a submarine built entirely by Japan. Although this will break past practices, it will not be shocking if Japanese submarines appear in the navies of other countries in the future.