Recently, at the 57th Japan Battery Conference, Huawei's Central Research Institute Watt Lab introduced high-temperature long-life lithium-ion batteries, and also claimed to use graphene materials. Is there an exception this time?
According to Huawei's description, this technological breakthrough comes from three aspects: electrolyte additives, cathode materials and graphene.
Let's first look at Huawei's promotional video, how to describe this high-temperature long-life lithium-ion battery, what role does graphene play in it.
The length of this technical presentation is 2 minutes and 25 seconds. The real key is the two: 58 seconds - the graphene material is filled in the positive and negative electrodes perpendicular to the current collector arrangement; 60 seconds - graphite The olefins are placed in a parallel arrangement on the current collectors of the positive and negative electrodes.
From the battery technology point of view, the vertical alignment of the electrodes does not affect the diffusion of lithium ions, and the parallel arrangement on the current collector does not affect the current collecting effect. Moreover, there is no graphene distribution on the separator, so it does not cause lithium ion diffusion to be hindered, and the battery performance is lowered. According to the arrangement and presence of the graphene material, the heat can be effectively conducted from the electrode without affecting the battery performance. The short film mentions the idea and explanation of using graphene to conduct heat, thereby reducing operating temperature and extending battery life, which is feasible from a technical point of view. Whether from a graphene perspective or a battery perspective, Watt Lab's solution to using graphene to reduce heat throughout the battery's operating temperature and extend life is reasonable and feasible.
There have been many studies and reports on the process of high temperature decay and degradation of lithium batteries. The mechanism is roughly due to the harmful side reactions caused by high temperature and the degradation of battery material properties. However, improvements from electrolyte additives and cathode materials are not groundbreaking. Although both efforts are significant, they are very difficult to achieve. The development of lithium-ion batteries has become a mature system today, that is, any part of the system will affect Other parts. The improvement of battery performance is actually the result of mutual improvement and balance between various parts, so the workload and difficulty of this. It's all huge.
The third solution, which is full of delusions, uses graphene to improve the heat dissipation of the battery, thereby reducing the operating temperature and extending battery life. At present, the commercial grade graphene heat conductive film can achieve 1200W/K m, and has been widely used for heat dissipation of high-power electronic components. It is very reasonable to use the high thermal conductivity of graphene to conduct the heat generated by the operation of the lithium ion battery from the inside.
However, Watt Lab did not specify the energy density of the battery. In this regard, many professionals have pointed out that when so many graphenes are added to the battery system for conduction, the space and quality of the active material of the same size battery will be reduced by graphene, which is certain. Will reduce the energy density of the battery, the capacity density data of this long-life high-temperature lithium-ion battery will not be "very good". The design of this battery should not be for automotive power batteries and drone power batteries with increasingly demanding energy density. It should be only energy storage batteries that are less sensitive to energy density requirements. Is this another hype of graphene batteries?
In fact, the lithium-ion battery industry needs new ideas for looking at graphene. Although some lithium-ion battery manufacturers are very motivated to introduce graphene materials, they still use old eyes to treat graphene instead of carbon materials (such as carbon black and graphite), using their high conductivity as a conductive agent, or using Graphene's high lithium storage is used as a negative electrode material, which is the main direction for improving battery performance. However, the actual evaluation results show that graphene has no advantage in this respect, or there are big problems that cannot be used. Graphene is a high-grade carbon material that has advantages and disadvantages compared with traditional carbon materials. Traditional carbon materials are very suitable for the existing lithium-ion battery system, but the introduction of graphene by cat-painting tigers is often worth the loss. Graphene also has functions not found in conventional carbon materials, such as high thermal conductivity, high strength, and two-dimensional unique morphology.
Huawei introduced a high-temperature lithium-ion battery using graphene, which does not utilize conductivity but uses heat dissipation, which proposes a new solution. Looking at graphene from a material point of view and developing an application solution, not just a simple replacement evaluation from the perspective of the battery, is a new idea of ​​using graphene. The same is true for other new materials. Lithium-ion battery manufacturers who can take the lead in realizing this change may be able to prioritize product technology upgrades and even innovations, and have an advantage in future competition.
From the graphene industry, Huawei's battery is also a signal: the current core of the graphene industry is not to do graphene, but to do graphene application solutions.
After years of development, graphene powder has been prepared from the laboratory grade of 5 years ago, and has expanded to the current tons of production. The price has been reduced from one gram to several thousand gram to one gram two or three yuan. The graphene preparation process has been Great progress. However, the downstream application of graphene has not been opened, and the thunder and rain have been small. A lot of graphene production is still focused on whether it is 1 layer or 2 layers or even 10 layers (graphene product specifications, in principle, graphene refers to single-layer graphene.), specific surface area is 300 square meters / gram or 500 square M/g, even use this content as a highlight to promote customers. However, from Huawei's short film, it can be clearly seen that Huawei does not emphasize the performance of graphene itself, but rather describes its use, that is, the arrangement, which is a kind of high thermal conductivity of graphene. solution. The core technology of this battery using graphene is not whether to use single-layer graphene, but how to achieve the arrangement in the lithium-ion battery and the choice of graphene.
Therefore, the graphene industry can only open the graphene application market by fully understanding the market, grasping the "pain point" of customers, providing customers with solutions with demand, and providing graphene products and using technologies.
Finally, I borrowed a sentence from Dr. Zhang Yujie from ATL (a well-known lithium battery manufacturer) as a summary: practice basic skills and use imagination. Practicing basic skills means that graphene manufacturers have to dig out the unique properties of graphene. The imagination is that lithium-ion battery manufacturers need to use new insights to discover the potential performance of graphene.
Precision Plus Ground and Whirled Ball Screw Assemblies are the highest precision product available, with standard lead accuracies of ±6µm/300mm. These ball screw assemblies feature a FL-Style ball nut, precisely preloaded to customer specifications. This unique nut design provides high repeatability and high stiffness for the most demanding ball screw applications. Each nut comes standard with awiper to protect against chips and other debris.
Miniature Metric Precision Ball Screws are an efficient and cost-effective solution in a small envelope, ideal for use in small spaces. Ball screw assemblies range from 4 to 14mm in diameter with leads from 1 to 20mm - all with standard lead accuracies of ±52µm/300mm. Miniature Rolled Ball Screws are ideal for laboratory, semiconductor, and medical applications.
Diameter
Pitch
Cycle mode
Nut Type
R/L thread
Raw Material
Surface Finishing
End Shaft Journal
4
1
I
F
R/L thread
S1
S2
S3
S4
G
CR
WS
MS
BR
BL
K
R thread
5
1
I
F
R/L thread
6
1
I
F
R/L thread
A
R/L thread
S
R thread
K
F
R thread
2
I
F
R/L thread
A
R/L thread
6
E
F
R thread
8
1
I
F
R/L thread
A
R thread
S
R thread
C
R/L thread
K
F
R/L thread
2
I
F
R/L thread
A
R thread
S
R/L thread
K
F
R/L thread
2.5
I
F
R thread
A
R thread
4
U
F
R thread
P
F
R/L thread
5
P
F
R/L thread
8
P
F
R thread
E
F
R/L thread
10
2
I
F
R/L thread
A
R/L thread
K
F
R/L thread
3
I
F
R/L thread
4
I
F
R/L thread
A
R thread
W
F
R thread
10
E
F
R/L thread
12
1
I
F
R/L thread
2
I
F
R/L thread
A
R/L thread
3
I
F
R/L thread
4
I
F
R/L thread
A
R thread
5
I
F
R thread
A
R thread
C
R thread
E
F
R/L thread
8
P
F
R thread
10
W
F
R/L thread
14
2
I
F
R/L thread
3
I
F
R/L thread
4
I
F
R/L thread
5
I
F
R/L thread
16
2
I
F
R/L thread
4
U
F
R/L thread
5
I
F
R/L thread
U
F
R/L thread
10
I
F
R/L thread
U
F
R/L thread
16
E
F
R thread
20
4
U
F
R/L thread
5
I
F
R/L thread
U
F
R/L thread
10
U
F
R/L thread
25
4
U
F
R/L thread
5
I
F
R/L thread
U
F
R/L thread
6
U
F
R/L thread
10
I
F
R/L thread
32Mm Ball Screw,Sfu1204 Ball Screw,Ground Ball Screws,Ground Miniature Ball Screw
SCREW TECHNOLOGY CO., LIMITED , https://www.screw-tech.com