The application of lithium-ion batteries not only saves space and reduces costs, but also solves the problem that each battery capacity must be matched with each other when batteries are combined in series, thereby increasing energy density and improving their reliability; and lithium-ion batteries have no memory effect , No environmental pollution. As a new type of secondary battery, with the continuous improvement of its performance, such as its cycle performance, low temperature performance, storage life and safety, etc., it must have a wide range of applications in the field of military equipment.

At the end of the 1970s, lithium primary batteries have begun to be used in military equipment and space equipment. In the communications equipment of the US military, the primary batteries currently used mainly include alkaline zinc-manganese batteries and magnesium-manganese batteries. Storage batteries mainly include sealed cadmium/nickel batteries, valve-regulated sealed lead-acid batteries, MH/Ni batteries and lithium-ion batteries. Compared with commercial ordinary alkaline manganese batteries, lithium/thionyl chloride primary lithium batteries have excellent performance but higher manufacturing costs. The high-power type has not completely solved the safety problem of explosions due to thermal runaway, so it has not been widely used. . Lead-acid batteries have low specific energy, large volume, and pollution to the environment. Zinc-manganese batteries have low specific energy and poor storage performance. Nickel-cadmium batteries have low specific energy and have a memory effect. The thermal battery increases the volume and mass of the battery due to the auxiliary heating system. In contrast, lithium-ion batteries have more advantages, so it is extremely urgent to develop high-performance lithium-ion batteries for various military equipment and aerospace fields. At present, lithium-ion batteries are mainly used in the military for portable communication equipment, automatic weapons, space energy, and GPS. The United States Rayovac Company and Covalent Company have researched and developed lithium-ion battery technology for underwater unmanned detection devices. The cycle life of this battery is much longer than that of a lithium metal negative battery. Rayovac has signed a contract with the U.S. Navy to develop negative electrode materials for large-capacity lithium-ion batteries, and subsequently will develop a single battery with a capacity of 20A·h. The U.S. Department of Defense is very interested in the development of lithium-ion batteries with good low-temperature performance. It has also established cooperative relationships with various well-known universities and research institutes to meet the development needs of space stations and portable military equipment.

Lithium batteries are used in military equipment and aerospace equipment

Portable weapons used in land, sea, and air operations, especially the Army’s ground operations, will require secondary batteries with high specific energy, excellent high and low temperature performance, light weight, miniaturization, simple logistics supply, and low cost; lithium-ion batteries for military communications and aerospace applications are also trending High safety and reliability, long cycle life, high specific energy and light weight. Therefore, the research on lithium-ion batteries with good environmental adaptability, high specific energy, high safety, and small and lightweight is the current hot spot and future development direction.

Lithium-ion batteries are the focus of the development of military communication batteries. At present, their specific energy by weight has reached 150W·h/kg, and the next goal is to increase to 170~200W·h/kg. The use of lithium-ion batteries in communication equipment must also first solve the safety problems in use. Because this kind of battery has light weight, high capacity, excellent electrical performance and charge retention performance, but the safety problem is also very prominent. In recent years, while increasing the specific energy of batteries, research on battery safety and low-temperature discharge performance has been strengthened. In addition to the short-circuit, overcharge, over-discharge, puncture, squeeze, temperature shock, and combustion test, the safety test also adds the content of the gun shot test to ensure that the battery will not burn or explode when used in wartime and harsh environments. .

Military Communication Batteries

In the research of lithium-ion battery safety technology, it is necessary to pay attention to the research on the optimization of its comprehensive performance, that is, to further improve the performance of the battery under the premise of ensuring the safety of the battery. That is, by controlling the amount and ratio of the positive and negative active materials of the battery, using a separator material with thermal closure function, adding additives that can resist overcharge and overdischarge in the electrolyte, strictly controlling the process and production environment, and on the single battery With the explosion-proof cover, the battery pack plus short-circuit, overcharge, over-discharge protection circuits and PTC protection components and other safety measures, the safety problem has been better solved. Avoid explosion and combustion in various experiments. Take the 18650 battery as an example. Discharge to 2.75V at 0.2C and 5A at -40°C, which can discharge a capacity of more than 30% of the rated capacity at room temperature. The 14.4V, 1.9A·h lithium-ion battery pack is discharged to 10V at 0.2C, 5A at -35°C, and can discharge a capacity of more than 70% of the rated capacity at room temperature. This shows that military communications lithium-ion batteries have made good progress in improving their low-temperature discharge performance. The monthly charge retention capacity has now increased to 92%~96%, which is equivalent to the international advanced level.

Whether the newly developed torpedo is a light (such as the MU90 torpedo) or a heavy (such as the "Black Shark") torpedo, its speed must reach more than 50kn. Therefore, the light torpedo needs more than 100kW and the heavy torpedo needs about 250 ~ 300kW. Torpedoes provide a limited length of energy storage batteries. Generally, light torpedoes with an outer diameter of 320mm provide batteries with a length of about 650mm; heavy torpedoes with an outer diameter of 530mm provide batteries with a length of about 1800mm. War torpedo batteries are generally aluminum/silver oxide batteries. Due to the difference in performance between zinc/silver oxide secondary batteries and aluminum/silver oxide batteries, if zinc/silver oxide batteries are used as batteries for the "Black Shark" torpedo, a single battery of 1400g/65A·h/1.32V is required. 37×8=296 cells, the length of the battery pack is 174cm, a total of 410kg, but it cannot meet the requirements for high-speed launch. In this case, it is usually necessary to meet the speed requirements for power and shorten the sailing time, but the sailing time is too short to still affect the training effect. In order to meet the requirements of new high-speed electric lightning, the French Saft Company and the American Yadner Company conducted research on the feasibility of lithium-ion batteries for lightning operation. The internal resistance of the battery also improves the shock and vibration resistance of the battery, so that the battery meets the requirements of environmental experiments suitable for lightning.

With the continuous improvement of the high-current discharge performance of lithium-ion batteries, research on lithium-ion batteries alone to combat thunder batteries is also being carried out. A new type of light torpedo developed by the U.S. Navy's Underwater Warfare Research Center in Newport, the southeastern city of Rhoad Island, uses a lithium-ion battery and an aluminum/silver oxide battery to form a hybrid power source, with a motor and a propeller. The integrated new propulsion device is the propulsion system, which combines the new technology of chemical power supply and the new technology of power propulsion, so that the specific energy of the entire power section is improved, and the overall performance of the torpedo is improved. The use of lithium-ion batteries can be used repeatedly during training with its rechargeable characteristics, allowing charging without disassembling the carrier, reducing the cost of the entire life cycle, and meeting the requirement of sufficient training times for the troops.

The French company Savotte has conducted applied research on naval equipment. The main goal is to use lithium-ion batteries in submarines (including nuclear submarines and conventional submarines), all-electric ship AES, and underwater unmanned navigation device UUV.

Lithium-ion batteries for submarines 

At present, submarines in various countries still mainly use lead-acid batteries as their power source for propulsion. According to NAVAL FORCES comments, the lithium-ion batteries developed by French SAFT for submarines have the following advantages compared with lead-acid batteries for submarines: quality is 3 times that of lead-acid batteries; cycle life is 3 times that of lead-acid batteries; maintenance-free; No memory effect. At the same time, a comprehensive analysis of safety is carried out. Due to the use of various types of temperature sensors and voltage sensors, the data is concentrated in the battery management system including safety measures, which can effectively avoid overcharging, short circuit, overheating or the like. SAFT has already introduced lithium-ion batteries for submarines in 2003. The Dauphin module used in the "Dauphin" system has an energy of 9kW·h, an average voltage of 3.5V, a mass of 120kg, and a volume of 60L.

The application of lithium-ion batteries in all electric ships (AES) also shows a competitive advantage. In addition to integrated electric propulsion, the all-electric ship also includes advanced prime movers and full electrical equipment for auxiliary equipment. The development of all-electric ships has provided a huge market for the development of certain storage batteries. The advantage of lithium-ion batteries for all-electric ships is: provide high working voltage, whether wound or block lithium-ion batteries can provide a voltage higher than 700V during the required working cycle; energy can be dispersed and stored in There are enough batteries to ensure enough navigation energy; due to the high specific energy, the battery pack is of low quality, there is no hydrogen evolution, oxygen evolution, safety and reliability, and long working life.

There are roughly three types of underwater unmanned navigation devices. ①All kinds of underwater shapes with underwater robots as the main body are like certain underwater creatures, and can automatically perform a certain task of underwater intelligent devices; ②Can perform mine search, interference, and track and tail submarines with targets, etc. Underwater self-propelled vehicles with recognition capabilities, environmental data detection capabilities, and communication capabilities are commonly referred to as AUVs (autonomous underwater vehicles); ③ a future underwater weapon similar to submarines with offensive capabilities. At the end of the 20th century, the U.S. Underwater Weapons Research Center and the Power Ship Company jointly formulated the MANTA plan to develop this type of new equipment, which is the main component of UUVs (unmanned undersea vehicles) research. The power demand of underwater navigation equipment is the focus of underwater power battery competition. At present, zinc/silver oxide batteries, lithium/thionyl chloride batteries or lead-acid batteries are mostly used in underwater navigation devices. Many lithium battery research units are designing and developing corresponding lithium-ion batteries for UUV and AUV. For example, the lithium-ion battery pack designed by the American Yadner Company for UUV is replaced by a 10kW·h, 423V zinc/silver oxide battery pack with 90 8A·h monomer packs, and is equipped with a monitoring and homogenizing charging device.

Potential uses in other areas are as follows
(1) Electric heating quilt
The electric heating quilt made of carbon fiber can greatly reduce the weight of the quilt, and it also has the incomparable thermal insulation performance of the traditional quilt. It is understood that high-latitude countries such as the Netherlands and Sweden plan to equip their military with electric heating quilt. The US military also plans to install special air conditioners on military uniforms to improve the combat conditions of officers and soldiers in tropical areas. If equipped with a lithium-ion battery, the quality and volume of the clothing will be greatly reduced.

(2) Power supply for airborne, vehicle-mounted and shipborne communication equipment
At present, the power supply or UPS used in airborne, vehicle-mounted and shipborne communication equipment generally uses lead-acid batteries. If lithium-ion batteries are used instead, the quality of the equipment will be greatly reduced and the communication time will be prolonged.

(3) Portable or small power supply
When the troops camp in the field, they rely on generators for power supply, but the sound and radiant heat of the generators will reduce their concealment. If the power source made of lithium-ion batteries is used to supply power to the command post and field hospitals, the concealment can be improved.

Modern warfare is mainly a war under high-tech conditions. The high-tech level of military equipment is an important indicator of a country's national defense strength. Various equipment of the navy, army and air force, especially the portable weapons used in ground operations of the army, will require secondary batteries with high specific energy, excellent high and low temperature performance, light weight, miniaturization, simple logistics supply, and low cost; lithium for military communications and aerospace applications Ion batteries also tend to have high safety and reliability, long cycle life, high specific energy and light weight. Therefore, the research on lithium-ion batteries with good environmental adaptability, high specific energy, high safety and small and lightweight is the current research hotspot at home and abroad and the future development direction. In today's increasingly scarce petroleum resources, the widespread application of lithium-ion batteries in military equipment will enable the miniaturization, weight reduction and energy saving of military equipment.