Zinc-silver batteries are the most energetic aqueous batteries. So far, zinc-silver batteries have undergone more than 100 years of development. The theoretical energy density of zinc-silver batteries is 300W·h/kg, 1400W·h/dm3, and the actual energy density is 40~110W·h/kg, 116~320W·h/ Dm3. The first successful zinc-silver oxide battery system was invented in 1941 by the French professor Henri Andre. At present, the research direction of zinc-silver batteries is to further improve the specific characteristics of zinc-silver batteries, bipolar design and increase the discharge density of active materials.
Zinc-silver batteries can be divided into three categories according to the nature of their work.
The first type is the primary battery (or primary battery), the second type is the battery (or secondary battery), and the third type is the storage battery (or activation battery). Zinc-silver batteries can be divided into two types of six types of batteries according to the structure and characteristics of the battery. The first type is non-charged state (or dry-discharge type), and the second type is charged state battery. The first type of battery is a manually activated battery, and the battery needs to be subjected to 1 to 3 charge and discharge cycles before use.
The second type of battery is divided into two types: dry type and wet type. Dry type refers to manual activation of primary or secondary batteries and automatic activation of batteries. Wet type refers to primary battery, button battery, primary secondary battery or fully sealed battery. The main feature of the dry type is that the battery cannot output electric energy before use, and an activation process is required; the main feature of the wet type is that the battery has the ability to output electric energy before use, and can be used mainly by connecting the electric device. Whether dry or wet, these batteries do not require charging before use. Zinc-silver batteries can be classified into five categories according to discharge rate classification. The first type is a low-rate battery with a discharge rate of less than 0.5C; the second type is a medium-rate battery with a discharge rate of 0.5 to 3.5C;
The third type is high-rate battery, the discharge rate is 3.5~7C; the fourth type is ultra-high rate battery, the discharge rate is greater than 7C; the fifth type is button battery, the discharge current is no more than 1mA. The classification of zinc-silver batteries is not independent of each other, but is related to each other.
Advantages and disadvantages
Zinc silver batteries have the following advantages:
(1) has a high specific energy;
(2) has a high discharge efficiency;
(3) has moderate charging efficiency;
(4) has a relatively stable discharge voltage;
(5) having a small self-discharge rate;
(6) has a long dry storage life;
(7) has good mechanical properties.
At the same time, zinc-silver batteries also have obvious deficiencies, and their shortcomings are as follows:
(1) High cost;
(2) Short life;
(3) poor low temperature performance;
(4) Not overcharged
Zinc-silver batteries have the following main applications:
(1) High-rate battery: This type of battery has superior high-current discharge performance and can be used as the main power source for various missile launch vehicle control systems, servos, engines, etc. It can also be used as a target machine and various Aircraft start and emergency power supply.
(2) Medium-magnification battery: The working voltage of zinc-silver battery is very stable, and it is more remarkable when working at medium and low magnification. In the telemetry system, external measurement system, safety self-destruction system and instrument cabin of missiles and rockets, Such batteries are widely used.
(3) Low-magnification battery: The low-magnification battery not only has stable voltage, but also has reliable performance. It is suitable for on-ball or arrow-on instruments with high voltage stability. Sealed zinc-silver battery can also be used as service life. The main power supply for returning satellites in days to ten days.
(4) News photography battery: Due to its stable performance, small size, light weight, simple use and maintenance, zinc-silver battery is used by various film studios, central and local TV stations for news photography, TV photography and lighting power supply.
Use of silver zinc battery
Silver-zinc batteries may replace existing lithium-ion batteries
At present, the biggest obstacle to the rapid development of mobile devices is the problem of batteries. Whether mobile phones, MP3s or laptops, how to extend battery life is the biggest headache for manufacturers. Currently, most mobile devices use lithium-ion rechargeable batteries, but since last year's "Sony battery door", the safety of lithium batteries has become more and more concerned.
A company called ZPower is trying to replace lithium-ion batteries. They use silver-zinc materials instead of lithium ions, which have advantages in terms of safety and energy density. It is said that the capacity of the ZPower battery is 30% higher than that of the same volume of lithium battery, and it can even be overcharged to achieve higher capacity without compromising safety. The battery uses a zinc polymer anode and a silver nanoparticle cathode. Since its internal storage unit is based on water, the safety is similar to that of a conventional alkaline battery, and its material is 95% recyclable.
The current problem is that the charging life of silver-zinc batteries is only about 100 times. ZPower hopes to increase to 200 times in the middle of next year and increase to 300 times in 2010.