How to evaluate the domestic power cell technology level?

improving product consistency are widely concerned topics in the power battery industry. The production cost curve is constantly fluctuating, and the consistency of products is not easy to quantify. To evaluate the technical level of power battery enterprises, comparing the energy density of cells is the most intuitive method.

In this paper, the ternary battery as an example, according to the square shell, cylinder and soft package three packaging system, referring to the views of some people, do not releasespecials, energy density as the standard to analyze the domestic power battery enterprise technology level.

Square shell: ningde era and byd, perhaps not backward

According to the official data, the energy density of the square shell cell has reached 240Wh/kg at the present stage of ningde era, and the technical plan is to increase the energy density of the cell to 300Wh/kg by 2020.

Through 811 ternary positive pole + silicon/carbon mixed negative pole to improve the energy density, at the same time, cycle, high temperature performance, cost, safety, etc. have to make a sacrifice, and at the same time the production process and environmental requirements are relatively harsh. Sources familiar with the matter told the first electric network that in 2017, the energy density of square shell cells supplied in large quantities by ningde times was between 190 and 210 wh/kg, which is likely to be increased to 210 to 230Wh/kg in 2018.

As early as the beginning of 2017, ningde era started the project of "industrialization technology development of a new generation of lithium ion power battery", developing lithium ion power battery with positive electrode of high nickel ternary material and negative electrode of silicon carbon compound. In 2017, the total output of ningde times was 17. 09Gwh, and just released the new version of the prospectus, when the west lake lithium ion battery production base project reached the postproduction, ningde times will add capacity of 24GWh, the total capacity will reach 41. 09 GWH.

However, insiders of byd revealed that at present, the energy density of byd's large-scale production cells is 220Wh/kg, and the target is to achieve 300Wh/kg by 2020. Today, byd's power battery has a total power of 16GWh, including 9GWh for lithium iron phosphate batteries and 7GWh for ternary lithium batteries.

Internationally, the square shell cell is samsung SDI's main products. In 2017, zheng shixiong, vice President of samsung SDI corporation, said publicly that the energy density of samsung SDI power battery is currently 250Wh/kg, and it is expected to reach the target of 350Wh/kg by 2023. Perhaps samsung has really achieved mass production of 250Wh/kg square shell cells in 2017, but NCA ternary anode materials are likely to be used.

There are many kinds of square shell batteries, and battery enterprises can customize the capacity, shape and size according to customers' requirements. Considering the difference of anode and cathode material formulations, the energy density between square shell cells with the same specification is more comparable. The gap between domestic and foreign leading enterprises in battery cell energy density may be very small, and China may not be far behind in terms of this technical condition alone.

Cylinder: can bick surpass panasonic?

As one of the few domestic companies focusing on cylindrical power batteries, bick said to the first electric network, its 2. The energy density of 75Ah power cell (18650) has reached 240Wh/Kg, and it is planned to achieve 300Wh/Kg in 2020.

Bick is also working on a 21,700 cylindrical power cell with a high energy ratio. Officially, compared to the 18650, the energy density of the 21700 is 35% higher (at 324Wh/kg?). Currently, it has the capacity for mass production and is expected to achieve mass production in 2018.

Bick's two production bases in shenzhen and zhengzhou, with a total annual capacity of 8GWh. Capacity will be expanded to 12GWh in 2018. Bick's total annual capacity is expected to reach 20GWh by 2020.

According to the information released by tesla in 2017, the monomer energy density of panasonic's mass production of NCA18650 cylindrical power battery is around 250Wh/kg, while the monomer energy density of 21700 has reached 300Wh/kg. If bick can mass produce 21,700 cylindrical batteries in 2018, its energy density could surpass panasonic's 2017 level by nearly 8 percent.

Is it true? Panasonic has yet to publicly announce the latest commercialization of its technology in 2018. If bko can actually mass produce 324Wh/kg cylindrical cells in 2018, it could become the world's most energy-dense mass-produced power cell.

Software package: maybe more scientific

Soft package, as opposed to hard shell (square shell, cylindrical), is a common way of battery packaging, and therefore parallel with the cylindrical, square proportionate.

The energy density of soft pack cells in mass production has reached 230Wh/kg/kg, and the products of 250 ~ 260Wh/kg will be launched at the end of 2018. At present, the capacity of tianneng's soft-pack power battery is 2. From 5GWh to 3GWh, it will be expanded to about 8GWh in 2019, and the new capacity will all be the ternary soft package route.

At present, the cell energy density supplied by kainai new energy in mass production is 220Wh/kg, and the product in 2018 will reach 250Wh/kg. By the end of 2017, the total capacity of kanai new energy was 2GWh, which will be expanded to 6GWh by the end of 2018.

Guocuantech also disclosed in the record of investor relations activities that the company undertook the major science and technology project of 300Wh/kg high energy density of the ministry of science and technology of the people's government of China. The company has developed sanyuan 811 soft package cell, and the energy density has reached 302Wh/kg. At present, the company has started to build the pilot production line of related products, and the production line is planned to start in 2019.

Tian shuo, general manager of Beijing keyi power technology co., LTD., has analyzed the reasons for the enterprises to choose sanyuan soft package in undertaking the major special power battery cell project of the ministry of science and technology. "It must be much easier to complete a 300Wh/kg cell in a soft package."

Due to the poor mechanical strength of the soft core, the team forming process and thermal management have higher matching requirements, which is challenging to the BMS design of the whole vehicle enterprise. And some of the core components are not yet domestic, but with the maturity of the industrial chain, the prospect of large-scale localization is also expected.

It's easier to put up aspecial than to do anything

Although each major battery enterprise has its own main products, but in the research and development, for the square shell, cylinder and soft package of these three different systems of battery, the enterprise will have different degrees of involvement. No one will be hanged in a tree, perhaps at this stage of the market decided to promote the type of products, but in the long run, there will not be a unique technical route.

In today's power battery industry, capital injection, enterprise merger and acquisition and other news emerge in an endless stream. Various battery concepts and laboratory breakthroughs keep coming up one after another, such as frequent news refresh about "charging for 800km in one minute". Leaving aside commercialization to talk about technology is to play hooligan, each technology route has its own advantages and disadvantages, or ultimately the enterprise is good at what it can do, market choice, product talk.

The page contains the contents of the machine translation.