Compared to lead-acid batteries, lithium batteries have long cycle life, light weight, large operating temperature range and strong charge holding capacity.
As one of the major breakthroughs in the three-electric technology (battery, electric drive and electric control), lithium batteries have gradually become the mainstream products in the industry. For example, Tesla has adopted 18650 and 27100 batteries in succession, all of which are lithium batteries.
According to the national target of power density of power lithium battery, the energy density of power battery should exceed 300Wh / kg in 2020, and the energy density of power battery system needs to reach 260Wh / kg.
Tesla previously used 18650 battery (250Wh / kg) from the target is still a slight gap, but the 21700 battery system energy density of about 300Wh / kg has been compared to Tesla's triumph, the density of most domestic batteries only Between 100 ~ 150Wh / kg, the situation is not optimistic.
Since lithium batteries can not quickly find a breakthrough, perhaps a change of material is a kind of method, such as 'the king of new materials' - graphene, to know it but human known high strength, good toughness, light weight, high light transmittance , Good conductivity of the new nano-materials, set thousands of light in one.
Graphene polymer battery is not only higher than the energy and charging speed, which is exactly solve the pain point of today's electric car battery.Although the traditional battery through some fast charging scheme to greatly reduce the charging time, but compared to traditional fuel filling method, still need users With great patience.
However, graphene can bring us the surprise, can be regarded as 'scared', for example, as early as 2015, Huawei Watt Lab at Japan's 56th Japan Battery Conference released a fast charge technology, making a 3000mAh Graphene batteries charge only up to 48% for 5 minutes.
What is more, as early as 2014, Graphenano of Spain cooperated with University of Córdoba of Spain to study the first graphene polymer material battery. The graphene polymer material has a specific energy of more than 600 Wh / kg, Fully charged within just 8 minutes, it is simply the existence of BUG.
Geneva Motor Show as the earliest opening of each year's European Auto Show, is also one of the world's five major auto show, is considered in the automotive area is an important 'wind vane.' As early as last year, by the famous Italian car design company Pininfarina designed the right way new hybrid Concept car H600 amazing Geneva.
Affected by charging equipment, battery PACK and vehicle high voltage system, it is not easy for new energy vehicles to stabilize 3C charge (3C is 75% of charge in 15 minutes) and 50C is 1.2 minutes in full charge.
The new car is equipped with the latest "micro turbine generator extender + super battery" power combination, which belongs to the range of electric vehicles.One of the positive group graphene super battery self-developed concern, power battery system energy density up to 300Wh / kg, can withstand 50C 50M fast charge and discharge intensity, charge speed and charge times are the current mainstream battery technology several times to several times.
First, graphene battery mass dumb fire
Since the advantages of graphene batteries compared to lithium batteries, it stands to reason that more manufacturers should be able to gain the fishes, but for now, almost no mainstream manufacturers to adopt such batteries.
Fisker EMotion uses graphene battery materials and can travel 208 kilometers in nine minutes, with a maximum range of 644 kilometers and a top speed of 259 kilometers per hour, and is expected to be the first to be sold in the United Kingdom in 2020.
Although Fisker introduced Fisker EMotion, a graphene battery car, at the previous North American auto show, the reality of osteoporosis has led most to think rationally that this is just a concept product that represents cutting-edge technology.
And as one of the earlier Tesla rivals, Fisk's rapid fall, and battery technology gimmicks in recent years than the actual, so we have to doubt the authenticity of this concept and practicality.
Fisker recently announced that it would charge a 800-kilowatt solid-state battery for 1 min of production by 2023. However, no other figures have been released, and in fact it is unclear whether this technical patent by Fisk has passed.
From the upcoming Geneva Motor Show, it seems that only the Pininfarina brand of the Italian sedan and Ford Motor Co. of India's Mahindra & Mahindra Group will release graphene battery technology vehicles, and the latter (Pininfarina HK GT concept car) battery technology is from From the right partner car.
Single from the laboratory point of view, graphene can bring great benefits Ju-jun is not suspected, because the graphene battery is also known as the "money tool" or "thesis weapon." Do not believe to go to the University to see that, Leverage the amount of bar, but really practical stage, the basic dumb fire.
Speaking of dumb fire, such as the above-mentioned Graphenano company in Spain, although the official claims that the battery has many advantages, but in the eyes of the public, this is more exaggerated.
The specific energy of a graphene battery exceeds 600wh / kg, and this performance can be crushed nowadays (for example, the energy density of a single BYD lithium iron phosphate battery is 150 ~ 160Wh / kg);
Single full charge within just 8 minutes, a single mileage can be as high as 1,000 km;
Life is four times the traditional hydrogenated batteries, lithium batteries twice;
The weight is only half the traditional battery, and the cost is 77% lower than the lithium battery.
Interestingly enough, Graphenano was already confident that it plans to put the battery into production by 2015 and plans to experiment with two of the four biggest automotive companies in Germany, but four years have passed For a long time, Graphenano and its crazy graphene battery never appeared in our field of vision.
From its official website, the latest news is basically to participate in the national conference or graphene in other products (such as dental products.) Placed a vast electric car market, make money for medical supplies, or is the head show funny Either we overstated their product capabilities.
Second, there is no graphene battery?
Although the press is full of 'graphene batteries', in fact, the current graphene for battery applications, it is mainly used in lithium batteries for negative materials and for conductive additives. The so-called Graphene batteries, in essence, belong to lithium batteries.
For lithium-ion batteries, graphene as a carbon-based anode material, there is no way to fundamentally change the lithium-ion battery than the magnitude of energy in the battery inside the negative electrode instead of graphite, although the overall capacity of the battery can be improved and charging speed, However, the performance improvement effect is limited and did not reach the strength as mentioned above.
While the research by Stanley Cui, a team of professors at Nature Nanotechnology titled 'Air-stable and freestanding lithium alloy / graphene foil as an alternative to lithium metal anodes', indicates that the coated graphene material inhibits polysulfide compounds The reaction with the negative electrode reduces the loss of positive sulfur active material, has good air stability and cycling performance with an energy density of about 500 Wh / kg, but the present study is limited to forward-looking theoretical research, Mass production is still a long way.
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Of course, this is not hindered graphene battery market is the main reason, the main reason for the difficulty of mass production in its interior.
Full graphene batteries are costly and difficult to prepare, and it is almost impossible to mass-produce some of the surprising data now available from highly pure graphene cells that appear only in the concept phase or in the lab;
The function of 'doped graphene battery' on lithium battery is conductive agent or electrode lithium intercalation material, but compared with the low cost of traditional conductive carbon and graphite, the performance improvement brought by the former is not enough to attract the manufacturers;
Graphene material itself has a high surface area and other properties, and the current lithium-ion battery industry's technical system can not be compatible;
In addition, the impact of other materials (such as silicon in the negative electrode has a higher theoretical capacity) and the dispersion process is more difficult, restricting the application of graphene in lithium batteries.
In short, replace the lithium battery graphene battery in the short term is basically impossible; 'doped graphene lithium battery' although there are some applications, but the effect is not large enough to shake the current pattern.
Geneva Motor Show as a stage where all flowers bloom, such as graphene battery car forward-looking products, although able to grasp the eye, but I'm afraid in the short term can only be reduced to the concept of booth products.