Lithium batteries containing cobalt are better than those containing cobalt.
As an important raw material for lithium-ion batteries, cobalt can significantly increase the energy density of lithium-ion batteries. In order to replace cobalt, battery manufacturers often increase the use of nickel to increase the energy density of batteries. However, the increased use of nickel will lead to a reduction in the structural stability of corresponding electrode materials, which will affect battery life and safety.
Lithium batteries that still contain cobalt are therefore better at present, and it seems that the cobalt-free solution is still difficult to achieve. So there isn't much choice.
Basic properties of cobalt:
The chemical valencies of cobalt are +2 and +3. It does not interact with waterat room temperature and is stable in humid air. It is oxidized to form CoO when heated above 300°C in air and burns to Co3O4 when white hot. The fine metal cobalt powder made by the hydrogen reduction method can ignite spontaneously in air to form cobalt oxide. The electrode potential shows that cobalt is a moderately active metal.
Its chemical properties are similar to those of iron and nickel. Oxidation occurs at high temperatures. When heated, cobalt reacts violently with oxygen, sulfur, chlorine, bromine, etc. to form the corresponding compounds. Cobalt is soluble in dilute acid and is passivated in fuming nitric acid forming an oxide film. Cobalt is slowly attacked by hydrofluoric acid, ammonia and sodium hydroxide. Cobalt is an amphoteric metal.
What is the “cobalt-free battery”» what Tesla calls? How is it different from ternary lithium batteries?
Lithium battery.
1. A pure cobalt battery is a battery that uses a single cobalt-lithium material, while a lithium battery is a type of battery that uses lithium metal or lithium alloy as the negative electrode material and uses non-cobalt material. -aqueous electrolyte solution. Lithium batteries are divided into two types: lithium metal batteries and lithium ion batteries are currently widely used lithium batteries. The positive electrode material is a compound containing lithium ions, while the negative electrode material is graphite.
2. From a performance perspective, pure cobalt batteries have better capacity, but are more expensive and have poor chemical stability. Lithium batteries have the advantages of stable structure, cap ratiohigh acity and outstanding overall performance, but their safety performance is poor and their production costs are also very high. The advantages of lithium batteries are their high energy density, portability and long life. They are widely used in mobile electronic devices, electric vehicles and other fields.
3. From the above, lithium batteries are good.
Recently, the news that "Tesla may use cobalt-free CATL batteries in its domestic models" has caused a sensation in the new energy circle. At the same time, the capital market also caused a stir. quick decisions. In response, the stock prices of many cobalt companies instantly fell to the limit. So, what is the Tesla “cobalt-free battery” about? In this issue of Electric Pai's “Questions and Answers” section,Pai Ke will share his views with everyone.
Cobalt-free batteries, as their name suggests, are batteries that do not contain cobalt. Nowadays, most of our common ternary lithium batteries are NCM (Nickel Cobalt Manganese) or NCA (Nickel Cobalt Aluminum), they all contain more or less cobalt. The LFP (lithium iron phosphate battery) does not contain cobalt, so it is widely speculated that what Tesla is negotiating with CATL this time is a lithium iron phosphate battery. If the cobalt-free battery Tesla mentions is really a lithium iron phosphate battery, does this mean that Tesla will abandon ternary lithium batteries and switch to lithium iron phosphate batteries?
In fact, the battle between lithium iron phosphate batteries and ternary lithium batteries has never stopped. Compared with ternary lithium batteries, lithium iron phosphate batteries prhave the advantages of good thermal stability, high safety performance and long service life. For example, experimental results have shown that the remaining capacity of ternary lithium batteries is 66% after 3,900 cycles. The remaining capacity of the lithium iron phosphate battery is 84% after 5000 cycles. However, in terms of battery energy density, lithium iron phosphate batteries do not perform as well as ternary lithium batteries.
Before 2012, lithium iron phosphate batteries were basically the main technical route in China. However, when Tesla reached profitability in 2013, people saw the potential of ternary lithium batteries. In addition, the amount of new energy subsidies in China in recent years has been mainly linked to high energy density. However, previous lithium iron phosphate LFP batteries were difficultdifficult to meet the requirements of high energy density, so they were gradually phased out by many people. new energy passenger cars.
However, there are gains and losses. Even though ternary lithium batteries offer high energy density, their safety risks cannot be ignored. Especially in the NCM nickel-cobalt-manganese ternary lithium battery, the element ratio gradually changed from 5:2:3 to 6:2:2 and then to 8:1:1. The stability of the ternary lithium battery deteriorates and. Worse still, incidents of spontaneous combustion are frequently reported.
But just when everyone thought “cobalt-free batteries” were lithium iron phosphate batteries, Tesla dropped another smoke bomb, claiming that “cobalt-free batteries are not necessarily lithium iron phosphate batteries. At the same time, Tesla also revealed thatits self-developed power battery is a supercapacitor battery, which undoubtedly casts a layer of confusion on the "cobalt-free battery".
In fact, the supercapacitor is not a new concept. It has been widely used in auto start/stop batteries. The characteristics of supercapacitors are exactly the opposite of those of ternary lithium batteries, which are long life, high stability and low energy density. If the “cobalt-free battery” Tesla calls it is actually a supercapacitor, then changes across the entire electric battery industry will be disruptive. However, in recent years, we have not heard of technological subversion of supercapacitors. Instead, lithium iron phosphate batteries are constantly improving battery energy density with new technologies. Therefore, Paike believes that iThe cobalt-free battery Tesla mentions is unlikely to be a supercapacitor and the probability is higher to have lithium iron phosphate, or a combination of both.
The above represents the entire content of the “Questions and Answers” section of this issue of Electric Pai. What do you think is the “cobalt-free battery” Tesla mentions? Welcome to interact with us and leave a message below.
This article is from the author of Autohome Chejiahao and does not represent the views and positions of Autohome.