Lithium batteries for submarines are actually not that mysterious

The use of lithium batteries is called a 'revolutionary breakthrough' in submarine batteries by the media.

As we all know, batteries are the main power source for conventional submarines, as well as backup and emergency power sources for nuclear submarines. Therefore, the performance of the battery directly determines the performance and combat capability of the submarine. If the battery performance is not good and the power supply is insufficient, the submarine will not run far or fast, the maneuverability will be greatly limited, the charging time will be longer when it surfaced, and the risk of exposure will also be greatly increased. Because of this, the development and application of submarine batteries has always been highly valued by the world's submarine manufacturing countries.

So, what are the basic performance requirements for submarine batteries? What kind of batteries are currently used in submarines?

In general, the main performance requirements for submarine batteries are low cost, large capacity, long life, short charging time and good safety. Lead-acid batteries are one of the few batteries that are close to the main performance requirements. Therefore, since the First World War, most submarine batteries have been lead-acid batteries.

Lead-acid batteries have mature technology, high reliability, good safety, long service life, and easy maintenance. However, their shortcomings are their low energy density and low capacity, so they often need to be Hundreds of single batteries are used in series, causing problems such as large battery size, heavy weight, and large space occupation, and a huge auxiliary system must be configured to ensure work. For these problems of lead-acid batteries, there is not much room for technical improvement and improvement.

Compared with lead-acid batteries, the emergence of lithium batteries will theoretically greatly improve the performance of submarines.

First, the volume and weight of lithium batteries are smaller, and the electricity generated by the same volume is at least three times that of lead-acid batteries, which helps reduce the weight of submarines, save space, and improve The endurance and mobility of the submarine.

Secondly, the charging speed and high efficiency of lithium batteries can greatly reduce the charging time of the submarine, thereby enhancing the concealment and survivability of the submarine.

The third is that lithium batteries have no memory effect, and there is no need to follow too many strict battery charging and discharging requirements to extend their life. The submarine can be charged and discharged at any time according to mission needs and battlefield environment, which is effective Improve the operational flexibility of the submarine.

However, limited by the current technology and process level, lithium batteries still have many insurmountable problems. Therefore, their application prospects are questioned.

The first is security. Lithium batteries emit a lot of heat during use or charging and discharging, and the interior of the submarine is a completely enclosed space. If the heat dissipation problem is not solved well, it will increase the submarine’s infrared radiation and increase the submarine’s detectability risk. And affect the reliability and stability of the submarine, and even cause safety accidents such as fire.

The second is high cost. Under normal circumstances, the cost of lithium batteries is several times higher than that of traditional lead-acid batteries, and a large number of lithium batteries are required on a submarine, coupled with auxiliary systems, undoubtedly increase the cost of the submarine.

In view of these problems, the application of lithium batteries on submarines is still in its infancy, and it is not the most ideal submarine battery. In the future, on the one hand, it is necessary to further improve the production process of lithium batteries, reduce costs, and increase reliability, and gradually increase its promotion or popularity in submarines; on the other hand, it is still necessary to continue to develop other submarine batteries, such as fuel cells.