As we all know, the types of batteries include LEAD BATTERY, GEL BATTERY AND LITHIUM BATTERY. The service life of lithium batteries is the longest, and the price is also the highest. Next, let me introduce lithium batteries to you.
Lithium-ion batteries use lithium-containing metal compounds on the positive electrode in advance, and carbon (graphite) that can absorb and store lithium is used on the negative electrode. Through such a structure, electricity can be generated without melting the electrodes by electrolyte as in traditional batteries, thereby slowing down the aging of the battery itself, not only storing more electricity, but also increasing the number of charge and discharge times. In addition, lithium is a very small and light substance, so that batteries can have various advantages such as small size and light weight.
The lithium-ion battery often mentioned in the 3C industry is actually a lithium cobalt oxide battery. In a broad sense, a rechargeable lithium-ion battery refers to a graphite negative electrode, a positive electrode using cobalt, manganese or iron phosphate, and a battery for transporting lithium. An electrolyte composed of ions. The primary lithium-ion battery can use lithium metal or lithium-intercalated materials as the negative electrode. The development of the lithium-ion battery industry has been concentrated in the 3C industry for more than 20 years, and is rarely used in the energy storage and power battery (instantly requiring a large current) market with a larger market economy. This market covers pure electric vehicles and hybrid electric vehicles. Vehicles, medium and large UPS, solar energy, large energy storage batteries, electric hand tools, electric motorcycles, electric bicycles, aerospace equipment and aircraft batteries, etc. One of the main reasons is that the lithium cobalt oxide cathode material (LiCoO2, which is the most common lithium-ion battery) used in lithium batteries in the past is relatively expensive, and it is difficult to apply in special environments such as puncture, impact, high temperature and low temperature conditions. More importantly, it has been criticized for failing to meet people’s absolute requirements for safety. At the same time, lithium cobalt oxide batteries cannot achieve the purpose of fast charging and completely avoiding secondary pollution. Moreover, a protection circuit must be designed to prevent overcharging or overdischarging, otherwise it will cause danger such as explosion, and even the explosion of Sony batteries. The global brand NB industry has invested huge sums of money in recycling.
“Lithium battery” is a type of battery that uses lithium metal or lithium alloy as the negative electrode material and uses a non-aqueous electrolyte solution. In 1912, the lithium metal battery was first proposed and studied by Gilbert N. Lewis. In the 1970s, M. S. WhitTIngham proposed and began to study lithium-ion batteries. Due to the very active chemical properties of lithium metal, the processing, storage and use of lithium metal have very high environmental requirements. Therefore, lithium batteries have not been used for a long time. With the development of science and technology, lithium batteries have become the mainstream now. Lithium batteries can be roughly divided into two categories: lithium metal batteries and lithium ion batteries. Li-ion batteries do not contain metallic lithium and are rechargeable. Lithium metal batteries, the fifth generation of rechargeable batteries, were born in 1996, and their safety, specific capacity, self-discharge rate and performance-price ratio are superior to lithium-ion batteries.
Throughout the history of battery development, we can see three characteristics of the current development of the world’s battery industry. One is the rapid development of green and environmentally friendly batteries, including lithium-ion batteries, nickel-hydrogen batteries, etc.; the other is the transformation of primary batteries into batteries, which is in line with sustainable Development strategy; the third is to further develop the battery in the direction of small, light and thin. Among commercialized 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 lithium-ion batteries have high volume specific energy and mass specific energy, are rechargeable and non-polluting, and have the three major characteristics of the current battery industry development, so they have a rapid growth in developed countries. The development of telecommunications and information markets, especially the extensive use of mobile phones and notebook computers, has brought market opportunities for lithium-ion batteries. The polymer lithium-ion battery in the lithium-ion battery will gradually replace the liquid electrolyte lithium-ion battery and become the mainstream of the lithium-ion battery due to its unique advantages in safety. Polymer lithium-ion battery is known as “the battery of the 21st century”, which will open up a new era of storage battery, and its development prospect is very optimistic.
Shortcoming:
Intolerance to over-discharge: During over-discharge, the excessively embedded lithium ions will be fixed in the crystal lattice and cannot be released, resulting in accelerated shortening of life. Deep discharge (discharge when the voltage is less than 3.0V) is more likely to damage the battery, so it should be Avoid storing when there is no power. The battery loss is generally 500 times of full charge and discharge. Discharge from the highest voltage of 4.2V to 3V as 100, reduce the action of deep discharge by 80%, and change it to shallow discharge by 30%. The maximum voltage of the battery can be effectively maintained and maintained. For the long-term health of the battery, under the condition of high voltage, the cycle times of driving electronic equipment can be increased. According to different battery formulas, the effective redischarge times can even be increased by nearly five to ten times. Therefore, using extremely low power is the behavior that damages the durability of the battery, that is to say, the increased voltage may activate the maximum discharge capacity of the battery.
Intolerance to overcharging: When overcharging, the electrode deintercalates too many lithium ions and does not get replenished in time, which can lead to the collapse of the lattice for a long time, thereby irreversibly damaging the performance of the battery, and it is more likely that the charged ions are not easy to flow and the energy is accumulated. cause an overheating explosion. Therefore, when manufacturers ship and store lithium battery products, they usually leave less than one-third of the power. When the charger connector is continuously plugged in, the most important thing is to avoid maintaining a fully charged state. Electric batteries that use lithium batteries as energy sources Cars are often designed with a charging limit of about 70% based on this feature. Some products even recommend keeping it below 50% daily, so that the capacity decline will be relatively less, which also means that the lithium battery must be used frequently, and the internal storage must be properly used regularly. electron flow.
Aging and fear of heat: Unlike other rechargeable batteries, lithium-ion batteries will inevitably decline naturally and slowly during the use cycle. Even if they are stored and not used, the capacity will also decrease. The loss of lattice caused by the cycle, such an aging process is called loss is more appropriate), in addition to the qualitative change of the chemical material itself, but also related to temperature. The possible mechanism is that the internal resistance gradually increases. Therefore, electronic products with high operating current are more prone to heat decay. In addition, the influence of external air temperature should be avoided. Replacing graphite with lithium titanate seems to extend the lifetime.
