Lithium battery” is a kind of battery that uses lithium metal or a lithium alloy as the negative electrode material and uses a non-aqueous electrolyte solution. In 1912, lithium metal battery was first proposed and studied by Gilbert N. Lewis. In the 1970s, MS Whittingham proposed and Lithium-ion batteries have been studied. Due to the very active chemical properties of lithium metal, the processing, storage, and use of lithium metal are very demanding on the environment. With the development of science and technology, lithium batteries have become the mainstream.
Lithium batteries can be roughly divided into two categories: lithium metal batteries and lithium ion batteries. Lithium-ion batteries do not contain metallic lithium and are rechargeable. The fifth-generation lithium-metal battery of rechargeable batteries was born in 1996, and its safety, specific capacity, self-discharge rate, and performance price ratio are better than lithium-ion batteries. Due to its own high technical requirements, only a few companies in the country are producing such lithium metal batteries.
Working principle
Lithium metal battery:
A lithium metal battery is generally a battery using manganese dioxide as a positive electrode material, metallic lithium or an alloy metal thereof as a negative electrode material, and a nonaqueous electrolyte solution.
Discharge reaction: Li+MnO2=LiMnO2
Lithium-Ion Battery:
A lithium ion battery is generally a battery using a lithium alloy metal oxide as a positive electrode material, graphite as a negative electrode material, and a nonaqueous electrolyte.
The reaction occurring on the charged positive electrode is
LiCoO2==Li(1-x)CoO2+XLi++Xe-(electron)
The reaction occurring on the charging negative electrode is
6C+XLi++Xe- = LixC6
Rechargeable battery total reaction: LiCoO2+6C = Li(1-x)CoO2+LixC6
Positive electrode
Cathode material: There are many optional cathode materials, and most of the mainstream products use lithium iron phosphate. Different cathode m
aterial comparisons:
| LiCoO2 | 3.7 V | 140 mAh/g |
| Li2Mn2O4
|
4.0 V
|
100 mAh/g
|
| LiFePO4
|
3.3 V
|
100 mAh/g
|
| Li2FePO4F
|
3.6 V
|
115 mAh/g |
Positive electrode reaction: Lithium ions are embedded during discharge, and lithium ions are deintercalated during charging. When charging: LiFePO4 → Li1-xFePO4 + xLi+ + xe-discharge: Li1-xFePO4 + xLi+ + xe- → LiFePO4.
Negative electrode
Anode material: Graphite is mostly used. New research has found that titanate may be a better material.
Negative electrode reaction: Lithium-ion is deintercalated during discharge, and lithium ions are embedded during charging.
When charging: xLi+ + xe- + 6C → LixC6
When discharging: LixC6 → xLi+ + xe- + 6C
Purchase method
Lithium-ion batteries are classified into liquid lithium-ion batteries and polymer lithium-ion batteries. The electrolyte of a lithium-ion battery is fluid, and therefore, it is more unstable than a lithium polymer battery, hitting an external force, or using a charger that does not meet the standard, may cause the battery to explode. Many portable electronic products such as mobile phones and laptops use lithium batteries. In other words, many people have a “bomb” around them. For the sake of safety, you must pay attention to the following points when purchasing.
1. Is there a clear capacity? A battery that does not have a clearly labeled capacity (such as 1000 mAh or 1000 mAh) is likely to use a poor quality battery or a recycled battery. Many of the cheap batteries that are flooding the market are made using recycled batteries. Although the price is cheap, life is short and the quality is unstable. Inadvertent use may damage the phone.
2. There is no guarantee of standby time. Standby time is the continuous use time after the battery is loaded into the phone until the next charge. The batteries sold in the general market cannot guarantee the standby time for the customers. This is because the battery quality is unstable, and many inexpensive batteries use a poor quality battery, so the standby time is short.
3. Whether to install a security circuit board. Without a protective circuit board, the lithium battery is in danger of being deformed, leaking, or exploding. Under the vicious price-cutting competition, the companies are looking for a lower-cost protection circuit board, or simply omitting the device, making the market full of explosive lithium batteries. Consumers can’t tell if they have a protective circuit board from the outside, so it’s best to choose a reputable merchant to buy.
