At this stage, the advent of the highest specific energy system for new energy passenger vehicles has caused thinking

In recent years, China's new energy vehicle industry has made great progress
.
In 2017, the total production and sales of new energy vehicles in China reached 794,000 and 777,000 units, respectively, and the cumulative ownership reached 1.
8 million units
.
New energy vehicle technology has been significantly improved, vehicle technology platforms have become increasingly mature, and breakthroughs have been made in key component technologies
.
However, at the current stage, the development of the new energy vehicle industry is not sufficient, and some contradictions are gradually exposed, which has become a "stumbling block"
that hinders the development of the industry.

In terms of pure electric vehicles, the "range anxiety" caused by the short driving range and slow charging of electric vehicles has become a key problem
hindering the development of electric vehicles.
In this case, high specific energy batteries are increasingly optimistic
.

The "Medium and Long-term Development Plan of the Automotive Industry" stipulates that by 2020, the annual production and sales of new energy vehicles will reach 2 million units, the specific energy of the power battery will reach more than 300Wh/kg, and strive to achieve 350Wh/kg, the specific energy of the system will strive to reach 260Wh/kg, and the cost will be reduced to less than
1 yuan/watt-hour.

In order to achieve the requirements of "the cell monomer strives to reach 350Wh/kg, and the specific energy of the system strives to reach 260Wh/kg" in the "Medium and Long-term Development Plan of the Automotive Industry", the grouping efficiency of Pack must reach at least 74%
in 2020 。 Zhou Bo, director of the industry research department of the power battery application branch of the China Physical and Chemical Power Industry Association, said that according to statistics, the group efficiency of the pack of pure electric passenger cars equipped with ternary batteries in 2017 generally remained at about 60%-65%, and at the end of 2017, some companies made a breakthrough to increase the pack group efficiency of ternary pure electric passenger cars to 70%.

As far as the current grouping efficiency of ternary cells in the industry is concerned, it is far from what is expected by the plan
.

Due to the high specific energy of ternary cells and active material properties, in order to meet the strict technical requirements of passenger cars for battery systems and the safety and reliability of up to 10 years of life cycle, a large number of components need to be added in the grouping process, which is the main reason why the grouping efficiency of ternary cells in the
industry is generally not high.

On the other hand, improving the group efficiency can effectively reduce the quality of the pack, which is of great benefit
to the lightweight development of new energy vehicles.
Battery China believes that with the improvement of relevant policies on the energy density, energy consumption and other technical indicators of the new energy vehicle power battery system, it will force car companies to pay more attention to the group efficiency
of Pack than ever before.
For power battery companies, the grouping efficiency of Pack will become one of
the competitive priorities in the market in 2018.

Some clues
can be seen from the first batch of "Recommended Model Catalogue for the Promotion and Application of New Energy Vehicles" released by the Ministry of Industry and Information Technology of the People's Republic of China in 2018.
The most typical example is Zhidou Automobile (LZD7002BEV03), as an A00-class sedan, the system energy density of the power battery equipped with this model is as high as 158.
07Wh/kg, becoming the highest system energy density model in the current announcement
.
It is worth noting that the cell grouping efficiency of the system is as high as 77%.

According to Li Liguo, technical director of the battery system supplier, Keyi Power chose lightweight materials in the design of this battery system, which reduced the weight
of some systems while ensuring the strength of the shell.
At the same time, Keyi Power also integrated and optimized the load-bearing structure, electrical structure and safety structure of the Pack, customized and developed large modules and automated production lines for the model space, so that the space was fully utilized and the structural parts design became more reasonable
.
The optimized Pack is equipped with three-element square cells that are closely arranged, which greatly improves the space utilization of the Pack, saves structural parts, reduces the overall weight of the Pack, and greatly improves the efficiency of the group
.

Reducing structural parts and realizing the close arrangement of cells through the design optimization of Pack will be the direction of the development of ternary cell groups, so the industry will put forward higher requirements
for the reliability of single cells.
At the same time, the energy density of single cells has an important impact
on the energy density after system integration.
Keyi Power said that the battery system selects battery cell products with high energy density, excellent cycle performance and high consistency on the market, and achieves the best quality integration effect
through advanced lightweight and safety integration technology.

It is understood that this time Keyi Power chose the 120Ah battery cell product of the NCM532 system produced by Jiangsu Tafel for integrated assembly
.
The relevant person in charge of Jiangsu Tafel told the battery China network that in order to meet the market demand, the company has worked hard in the reliability of the product, through the optimization of the internal design of the cell, Tafel has developed and produced high-specific energy ternary cell products
that can achieve close assembly of modules.
Through scientific research and innovation, Tafel's battery cell products currently have more than 200 safety designs, which greatly improve the reliability
of single cells.
By strengthening management and strictly controlling the production process, Tafel will also launch battery cells
with higher energy and better reliability this year.
It is understood that the energy density of the battery cell product equipped with Zhidou is 205Wh/kg, and for the passenger car and special vehicle market, Tafel has launched a 135Ah ternary square cell, its energy density is as high as 215Wh/kg, and its cycle life is as high as 3000 times, which is a very competitive battery product
.
Tafel said that it will continue to launch mass production of 215-220Wh/Kg cells in the first half of 2018, and 230Wh/Kg cell products
from the end of 2018 to the beginning of 2019.

Li Liguo said that due to the impact of subsidy decline, frequent policy adjustments and rapid replacement of battery technology, the development cycle of new products of automobile companies is compact and the requirements for cost reduction are strong, and Keyi Power has clarified the product strategy of high energy density, high safety and low cost and the service strategy
of rapid development and rapid mass production.
The "model customization" model is more suitable for the future market development of model personalization and diversification, and improving the group efficiency of Pack as an important aspect of it, which is in line with the interests of car companies and will be an important direction
for future development.

Jiangsu Tafel also captured this market change, Tafel related person in charge said that the future development of high energy density of battery systems is inseparable from the lightweight of single cells
.
In addition to actively developing new high-energy density materials, Tafel has carried out forward-looking research on functional integration in battery structure, so as to achieve the purpose of reducing material and weight; At the same time, Tafel has also carried out research on functionalized and lightweight materials in inactive materials to reduce battery weight and battery costs
.

For the development of pure electric vehicles, the energy density of the battery cell and the group efficiency of the system are complementary, and battery companies should pay more attention to the topic of
group efficiency.
The "double sword combination" of Keyi Power and Tafel provides a new idea
for the industry to improve the energy density of electric vehicle systems.
In the future, the country's energy density requirements for new energy vehicle systems will be further improved, and by optimizing the internal structure of products, improving product reliability and improving cell group efficiency, it will also become a new choice
for the development of electric vehicles in the future.