Knowledge about the battery

Li-ion battery series problem


Since the battery in the production process, from start to become a finished film to go through a lot of working procedure. Even after rigorous testing procedures so that each power supply voltage, resistance, capacity of the same, but with a period of time, laptop battery will produce this or that difference. As a mother gives birth to twins, just gave birth may grow exactly the same as a mother it is difficult to distinguish. However, two children were growing, they will produce this or that differences in lithium battery power as well. Generate differences in the use of a period of time following the introduction of the overall voltage control approach is difficult to apply in lithium-powered batteries, such as a 36V battery stack, we must use 10 cells in series. The overall charge control voltage is 42V, the discharge control voltage is 26V. With the overall voltage control mode, the initial use of phase coherence are particularly good because the battery might not be any problems. After a period of time using the battery internal resistance and voltage fluctuations generated, forming an inconsistent state, (inconsistency is absolute consistency is relative) This is still used when the overall voltage control can not achieve its purpose. For example, 10 of which two battery discharge the battery voltage is 2.8V, four battery voltage is 3.2V, 4 only 3.4V, the current overall voltage is 32V, we let it continue to discharge worked to 26V. In this way, then two 2.8V batteries lower than the 2.6V is the over-discharge state. Lithium batteries is equivalent to a few over-discharge scrap. On the contrary, with the overall voltage control charging way charging, there will overcharge condition. For example using the above 10 state of the battery charging voltage at the time. The overall voltage reaches 42V, that's two 2.8V batteries in the \ "Hunger \" state, and rapid absorption capacity, it will more than 4.2V, while the overcharge of more than 4.2V batteries, not only by the high voltage generated scrap and will even dangerous, that is, the characteristics of lithium-powered batteries.

　　


Lithium-ion battery rated at 3.6V (some products are 3.7V). When fully charged the termination charge voltage and battery anode materials relate to: the anode material is graphite 4.2V; anode material for coke 4.1V. Resistance of different anode materials are also different, slightly larger internal resistance of coke anode and the discharge curve is also slightly different, as shown in Figure 1. Commonly referred to as 4.1V and 4.2V Li-ion battery Lithium-ion batteries. Now used mostly 4.2V, and the termination of lithium-ion battery discharge voltage 2.5V ~ 2.75V (battery factory operating voltage range is given, or given the termination of the discharge voltage, the parameters slightly different). IBM Laptop Battery Less than the termination of discharge voltage to continue to discharge known as the over-discharge, over-discharge of the battery will be damaged.

　　


Portable electronic products to the battery as a power supply. With the rapid development of portable products, all kinds of greatly increased battery usage, and has developed many new battery. In addition we are familiar with high-performance alkaline batteries, rechargeable nickel-cadmium batteries, nickel-metal hydride batteries, there is in recent years, the development of lithium batteries. This article introduces the basic knowledge related to lithium batteries.IBM ThinkPad A21 Battery, IBM ThinkPad A22 Battery, IBM ThinkPad A30 Battery, This includes its characteristics, the main parameters, models of meaning, application and use for attention.

　　


Lithium is a metallic element, its chemical symbol Li (its English name lithium), is a silvery white, very soft, lively and chemical properties of metal, the metal is the lightest. In addition to its application outside the atomic energy industry, can produce special alloys, special glass (TV screen glass used), and lithium batteries. In lithium batteries use it as a battery anode.

　　


Lithium batteries are also divided into two categories: non-rechargeable and rechargeable types. Non-rechargeable battery known as the disposable batteries, it can only be a one-time chemical energy into electrical energy, electrical energy can not be restored back to chemical energy (or restore the performance of poor). The rechargeable battery is called secondary batteries (also known as batteries). It would be chemical energy into electrical energy stored in the use of time, and then convert chemical energy into electrical energy, which is reversible, such as chemical energy lithium batteries power the main features.

　　


Smart portable electronics products require light weight and size of filial piety, but the battery size and weight compared with other electronic components are often the largest and most heavy. For example, I remember when the "Big Brother" is very "thick, heavy," while today's cell phone is so light. IBM ThinkPad A21 Battery, One improvement is the battery played a significant role: in the past is a nickel-cadmium batteries, lithium-ion batteries are now.

　　


The biggest characteristic of lithium batteries is higher than the energy. What is the specific energy then? Refers to the specific energy per unit weight or unit volume of energy. With the specific energy Wh / kg or Wh / L to represent. Wh is a unit of energy, W is watts, h is the hours; kg is 1000 grams (weight units), L is liters (volume units). To give an example to illustrate: 5, nickel-cadmium batteries rated voltage 1 2V, its capacity is 800mAh, then its energy 0 96Wh (1 2V × 0 8Ah). 5, the same size Lithium - Manganese Dioxide battery rated at 3V,IBM ThinkPad A21 Battery, IBM ThinkPad A22 Battery, IBM ThinkPad A30 Battery, its capacity is 1200mAh, then its energy of 3 6Wh. Both the battery size is the same, then the lithium - manganese dioxide battery is a nickel-cadmium battery specific energy of 375 times!

　　


1 5 nickel-cadmium batteries, weighing about 23g, while a 5 Lithium - Manganese Dioxide Battery weighs about 18g. 1 Lithium - Manganese Dioxide battery 3V, while the two nickel-cadmium battery only 2 4V. Therefore, when the battery using a small number of lithium battery (to reduce size of portable electronic products to reduce the weight of filial piety), and long battery operating life.

　　


In addition, the lithium battery with a discharge voltage stability, operating temperature range, self-discharge rate is low, storage, long life, no memory effect and pollution-free and so on.

　　


The drawback is that lithium batteries are expensive, so it is not yet widely used, mainly used in handheld computers, PDA, communications equipment, cameras, satellites, missiles, torpedoes, equipment and so on. Along with technological development, process improvement and production increase in the price of lithium batteries will continue to decline, applications will be more common.

　　


Non-rechargeable lithium batteries

　　


Non-rechargeable lithium batteries have a variety of currently used are lithium - manganese dioxide batteries, IBM ThinkPad A22 Battery, lithium - thionyl chloride batteries and lithium batteries and other compounds. This article describes only the first two of the most commonly used.

1, lithium - manganese dioxide batteries (Li MnO2)

Lithium - Manganese Dioxide Lithium battery is a kind of anode to manganese dioxide as cathode, and a one-time use of organic electrolyte batteries. The main characteristics of the battery cell voltage is high, rated voltage of 3V (an ordinary alkaline batteries 2 times); the termination of the discharge voltage of 2V; than the energy of large (see above examples); discharge voltage is stable and reliable; a good storage properties (storage time 3 years), self-discharge rate is low (annual self-discharge rate ≤ 2%); Operating temperature range -20 ℃ ~ +60 ℃.

　　


The battery can be made into a different shape to meet different requirements, it has a rectangular, cylindrical and button-shaped (button). There are also different cylindrical diameter and height measurements. Here are all the more familiar one # (size of the code D),IBM ThinkPad A21 Battery, IBM ThinkPad A22 Battery, IBM ThinkPad A30 Battery, 2 # (size of Code C) and 5 # (size of the code AA) batteries main parameters.

　　


CR is expressed as cylindrical lithium - manganese dioxide battery; five figures, the first two that the diameter of the battery, the latter three, said with a decimal level. For example, CR14505, whose diameter is 14mm, height of 50 5mm (this model is generic).

　　


Here we must point out that the same plant are different types of batteries may be some differences in their parameters. In addition, the standard discharge current value is smaller, the actual discharge current can be larger than the standard discharge current, and the continuous discharge and pulse discharge permit discharge current is different from the battery plant to provide relevant data. For example, Li Hing power produced by CR14505 gives maximum continuous discharge current of 1000mA, maximum pulse discharge current up to 2500mA.

　　


The camera using lithium batteries are mostly lithium - manganese dioxide battery. Here the camera commonly used in lithium - manganese dioxide battery included in Table 2, for reference.

　　


Button type (button) batteries smaller, its diameter 12 5 ~ 24 5mm, height 1 6 ~ 5 0mm.IBM ThinkPad A30 Battery, Several more commonly used button batteries as shown in Table 3.

　　


CR for the cylindrical lithium - manganese dioxide battery, the last four digits in the first two for the diameter size of the battery, the latter two with a decimal point for the height measurements. For example, CR1220 diameter of 12 5mm (not including the number after the decimal point), its height is 2 0mm. This model that is universal.

　　


This button batteries commonly used in clock, calculator, electronic notebook, cameras, hearing aids, IBM ThinkPad A21 Battery, IBM ThinkPad A22 Battery, IBM ThinkPad A30 Battery, electronic games, IC cards, backup power supplies.

　　


2, lithium - thionyl Chloride Battery (Li SOCl2)

　　


Lithium - thionyl chloride battery is the highest specific energy of a current can be achieved 500Wh/kg or 1000Wh / L level. Its rated voltage is 3 6V, medium-current discharge with a very flat discharge characteristics of 3 4V (available at 90% of capacity to discharge within the flat to keep small change). The battery can be -40 ℃ ~ +85 ℃, within the scope of work, but in -40 ℃ ambient temperature when the volume capacity of about 50%. Self-discharge rate is low (annual self-discharge rate ≤ 1%), storage life of up to 10 years.

　　


With a # (size of the code D) nickel-cadmium batteries and 1 # lithium - thionyl chloride battery than the energy to make a comparison: 1 # nickel-cadmium batteries rated voltage 1 2V, a capacity of 5000mAh; 1 # lithium - thionyl chloride rated voltage