​The development history of Lithium-ion battery (Part I)

In 1970, Exxon's MS Whittingham used titanium sulfide as the starting material and metallic lithium as the negative electrode material to assemble the first lithium battery. The transition material of lithium batteries is manganese dioxide or thionyl chloride, and is no longer lithium. After the battery is assembled, the battery has voltage and does not need to be charged. Li-ion batteries (Li-ion Batteries) are developed from lithium batteries. The so-called button batteries used in cameras in the past belonged to lithium batteries. This kind of battery can also be charged, but the cycle performance is not good. Lithium crystals are easy to form during the charge and discharge cycle, which causes the internal short circuit of the battery. Therefore, this kind of battery is generally prohibited from charging. In 1982, RRAgarwal and JRselman of the Illinois Institute of Technology discovered that lithium ions that have the characteristics of intercalated graphite. This process is fast and reversible. At the same time, the potential safety hazards of lithium batteries made of metal lithium have attracted much attention. Therefore, people have tried to make rechargeable batteries using the characteristics of lithium ions embedded in graphite. The first available lithium ion graphite electrode was …

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​The development history of Lithium-ion battery (Part II)

Throughout the history of battery development, we can see the three characteristics of the current world battery industry development. One is the rapid development of green and environmentally friendly batteries, including lithium-ion batteries, nickel-hydrogen batteries, etc.; the other is the conversion of primary batteries to batteries, which is consistent with sustainable development strategy; the third is to further develop the battery in the direction of small, light and thin. Among the commercial rechargeable batteries, lithium-ion batteries have the highest specific energy, especially polymer lithium-ion batteries, which can achieve thinner rechargeable batteries. It is precisely because of the high volume ratio energy and mass ratio energy of lithium-ion batteries, that they are rechargeable and pollution-free, and have the three characteristics of the current battery industry development, so they have a relatively rapid growth in developed countries. The development of the telecommunications and information markets, especially the extensive use of mobile phones and notebook computers, has brought market opportunities for lithium-ion batteries. With its unique advantages in safety, polymer lithium ion batteries in lithium-ion batteries will gradually replace liquid electrolyte lithium ion batteries and become the mainstream of lithium ion batteries. The polymer lithium-ion battery is known as the "battery of the …

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The key advantages of Lithium-ion battery

1) High voltage The operating voltage of the single battery is as high as 3.7-3.8V (3.2V for lithium iron phosphate battery), which is 3 times that of Ni-Cd and Ni-MH batteries. 2) High energy density The actual specific energy that can be achieved is about 555Wh/kg, that is, the material can reach a specific capacity above 150mAh/g (3-4 times Ni-Cd, 2–3 times Ni-MH). 3) Long cycle life Generally, it can reach more than 500 times, or even more than 1000 times, and it can reach 8000 times for lithium iron phosphate. For electrical appliances with low current discharge, the battery life will double the competitiveness of electrical appliances. 4) No pollution and no memory effect As the predecessor of Li-ion, the lithium battery is short-circuited due to the formation of dendrites due to metal lithium, which reduces its application fields: Li-ion does not contain cadmium, lead, mercury and other elements that pollute the environment: A major disadvantage of Ni-Cd batteries of some processes (such as sintered) is the "memory effect", which seriously restricts the use of batteries, but Li-ion does not have this problem at all. 5) Low self-discharge The self-discharge rate of fully charged Li-ion stored at room temperature …

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​The development trend of Lithium-ion battery

1) Polymers Polymer lithium-ion batteries are developed on the basis of liquid lithium-ion batteries, using conductive materials as the positive electrode, carbon materials as the negative electrode. The electrolyte is composed of solid or gel organic conductive film, and the outer packaging is the latest version of the aluminum-plastic film. Because of its more stable performance, it is also regarded as a replacement product for liquid lithium-ion batteries. Many companies are developing this new type of battery. 2) Power Strictly speaking, power lithium-ion battery refers to a lithium-ion battery with a capacity of 3AH or more. It generally refers to a lithium-ion battery that can be discharged to drive equipment, vehicles, etc. The capacity of the battery may not reach the level of unit AH. Power lithium-ion batteries are divided into two types: high capacity and high power. High-capacity batteries can be used for power tools, bicycles, scooters, miners’ lamps, medical equipment, etc.; high-power batteries are mainly used for hybrid vehicles and other occasions that require high-current charging and discharging. According to different internal materials, power lithium-ion batteries are divided into liquid power lithium-ion batteries and polymer ionic power batteries, collectively referred to as power lithium-ion batteries. 3) High Performance …

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​Do you know the 18650 Lithium-ion battery cell?

18650 is a standard lithium-ion battery model set by SONY, the originator of lithium-ion batteries, in Japan in order to save costs, where 18 means a diameter of 18mm, 65 means a length of 65mm, and 0 means a cylindrical battery. 18650 theoretical battery life is 1000 cycles. Due to the large capacity of the unit density, most of them are used in laptop batteries. In addition, because the 18650 has a very good stability at work, it is widely used in various electronic fields: often used in high-end strong light flashlights and portable power supply, wireless data transmitter, electric heating warm clothes, shoes, portable instruments, portable lighting equipment, portable printers, industrial instruments, medical instruments, etc. The mainstream capacity of 18650 batteries ranges from 1800mAh to 2600mAh (the capacity of 18650 power batteries is mostly 2200~2600mAh), and the mainstream capacity even has standard 3500 or 4000mAh or more.

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Brief introduction of LFP battery and NCM/NCA battery

Lithium Iron Phosphate Battery During the charging process, part of the lithium ions in the lithium iron phosphate are released, transferred to the negative electrode through the electrolyte, and embedded in the negative electrode carbon material; at the same time, electrons are released from the positive electrode and reach the negative electrode from the external circuit to maintain the balance of the chemical reaction. During the discharge process, lithium ions are extracted from the negative electrode and reach the positive electrode through the electrolyte. At the same time, the negative electrode releases electrons and reaches the positive electrode from the external circuit to provide energy for the outside world. Lithium iron phosphate battery has the advantages of high working voltage, high energy density, long cycle life, excellent safety performance, low self-discharge rate and no memory effect. Ternary Polymer Lithium Battery Ternary polymer lithium battery refers to a lithium battery that uses lithium nickel cobalt manganite (Li (NiCoMn) O2) or lithium nickel cobalt aluminate as the cathode material. The ternary composite cathode material is nickel salt, cobalt salt, and manganese salt as raw materials, the ratio of nickel, cobalt and manganese inside can be adjusted according to actual needs. The battery …

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​Advantages of lithium iron phosphate batteries

Lithium iron phosphate batteries, like lithium manganese oxide, lithium cobalt oxide, and ternary lithium batteries, are the branches of lithium-ion batteries. Its performance is mainly suitable for power applications. The advantage of lithium iron phosphate battery mainly refers to its comparison with other batteries in power applications. In this sense, it will mainly compare its relative advantages with ternary lithium batteries and lead-acid batteries. 1) The advantage of high temperature resistance compared with ternary lithium batteries. The high-temperature performance of lithium iron phosphate batteries is better, and can withstand high temperatures of 350°C~500°C, while lithium manganite/lithium cobalt oxide is usually only about 200°C. The materials of modified ternary lithium batteries will generally be decomposed at 200°C. 2) The advantage of long service life. Lithium iron phosphate batteries have a longer cycle life than lead-acid batteries and ternary lithium batteries. The "long life" of lead-acid batteries is only about 300 times, up to 500 times; the ternary lithium battery theoretically can reach 2000 times, and the capacity will decrease to 60% when it is actually used about 1000 times; while the true life of lithium iron phosphate batteries that is to say 2000 times with 95% capacity remained, and its conceptual …

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Common terminology of Lithium-ion battery (1)

Capacity The capacity of the battery is under certain discharge conditions, which is represented by the symbol C. The common unit is ampere hour, abbreviated as Ah or mAh. The capacity of battery can be divided into theoretical capacity, rated capacity and actual capacity. The theoretical capacity is the highest theoretical value obtained by calculating the mass of active substance according to Faraday's law. In order to compare different series of batteries, the concept of specific capacity is commonly used, that is, the theoretical capacity per unit volume or unit mass of battery, like Ah/kg (mAh/g) or Ah/L (mAh/cm3). The actual capacity refers to the power output of the battery under certain conditions. It is equal to the discharge current multiplying by discharge time, and its value is less than the theoretical capacity. The rated capacity is also called guaranteed capacity, which is the minimum capacity that the battery should discharge under certain discharge conditions according to the standards issued by the state or relevant departments.   Internal resistance The resistance is called the internal resistance of the battery. The internal resistance of the battery is not a constant, but changes with time during the discharge process, because the composition …

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