How Battery and Integration Technology Better Adapt and Match the Progress of "Four Modernizations"

In today's development and development of China's new "four modernizations" (electrical, intelligent, networked, and shared), the highly-compatible features are bound to be the future development trend. How to better adapt and match the "four modernizations" of electric core technologies and parts, batteries and integrated technologies requires not only breakthroughs in cell technology, but also the need for integrated technology to highlight its characteristics. As the saying goes, “Alone is not a forest,” and Xie Jiezheng sees that, during the development of new energy in these years, this has been fully confirmed, which is the battery integration technology that cannot be ignored.

Power Battery Integration Urgently Needs Innovation

"Battery as a power source, do not drag the new four hind legs." This warning is not alarmist. Electromobility is the first of the four new technologies. Battery is not only the core technology of electrification, but more importantly, there are too many problems that are not solved. “The Prime Minister visited Japan and saw what made him look dignified. Is the gap really so big?” This is a recent high-frequency word from the media. Although it is the matter of fuel cells, but our lithium-ion battery gap! It is undeniable that there is still a small gap in battery integration technology. From the silent yearning of foreign battery technology, "the core technology of Japan and South Korea, integrated technology to see Europe and the United States," this sentence is not groundless. In terms of technology, they use the advantages of materials, vehicle integration advantages and experience to apply to the development and application of power batteries. Of course, it is undeniable that the domestic level has made great progress. The rapid follow-up and improvement of standards is a typical symbol. Our advantage is still very obvious. We can use our market to drive industrialization (the market is right before us); use policies to concentrate and unify our resources. However, how to take advantage of advantages and opportunities to quickly catch up, still need to increase "innovation" efforts.

Higher requirements for battery integration

Security issues

Although Musk always complained after the tesla vehicle caught fire: Why did the media not pay attention to the accidents of traditional fuel vehicles? But I still think that the user is right and the customer's concern is right. Our technological innovation and progress have been to solve the user's concerns and to make the accident rate smaller. This is our responsibility. The battery safety problem, on the one hand, breaks through the internal nature of the battery core, and on the other hand it seeks a breakthrough from the "integrated" technology. At present, the most widely used monitoring technology, power-off technology, fuse technology, and thermal isolation technology do not seem to hold back tesla's fire. Still need to work hard.

Taken from May 25th Blacktech: "On a recent highway on Ticino in southern Switzerland, a German driver drove a Tesla Model S into a central barrier, and then the vehicle turned over and quickly caught fire. The driver was unfortunately trapped in the car. Burned inside, the Swiss fire department announced through Facebook that the cause of the fire may have been a "thermal runaway" after the vehicle's lithium battery crashed.

2. BMS Management Technology

Many times, the accuracy of SOC estimation has not been much improved. Still can not accurately capture the difference between working and stationary state of chemical energy, had to leave a margin of absorption capacity deviation at the end of the battery charge and discharge, so that the battery cost is wasted 5 to 10%. Foreign products, in this regard, are done in a more detailed manner. The accuracy of the SOC 16.35% calibration value from the leaf lower limit can be seen. Behind this is the bloody sense of cost pressure. Under the promotion of the new four modernizations, BMS is not only an accurate estimation problem, but also requires innovation and breakthroughs in its management functions, diagnostic functions, software strategies, hardware architecture, and integration and modularization.

3. Lightweight battery system

The weight of the battery has always been criticized. It has been a long time and it has been numb. Feelings are the scourge of batteries. However, from the recent period of time, when the concept of energy density was proposed in the work communication or the parameter table, it quietly changed. It is no longer the first place in the energy density of cells, but in front of the energy density, two words “systems” are heavily added. Some people have done statistics, the weight of electric vehicles is reduced by 10%, and the corresponding cruising range can be increased by 5.5%. In the leaf 2018 model, there are also traces of light weight, “the weight of the battery case is reduced, the number of screws used to fix the battery module is reduced, and the extra wall thickness of the bracket is removed, and the battery module is also lightened. Exterior."

4. Battery integration standardization process

The standardization of batteries is the most effective way to reduce costs. This problem has been seen by some manufacturers in the country as early as possible, and standard modular products have been born. However, the market efficiency is not very good. The reason for the study is that in the early stages of development, standardization needs to rely on certain platforms to survive. The domestic situation, even the most basic battery shape, still stays in a variety of forms. Although there are relevant standards in the country, the implementation effect is not satisfactory. Personally think that too many form factors in the standard, too much attention to the needs of diversified systems, equal to no standard. In contrast, VDA single-shell battery size standards, why can be recognized by many battery companies? Worth pondering. The standardization of batteries can effectively promote the modular development in battery integration.

Modular "Integration" Technology Innovation Development

1. Module's "new modularization" trend, horizontal "universal" multi-platform application

The concept of modularity is not a new term. As early as in 2012, Volkswagen's brand-new platform MMB/MQB/MLB has adopted modular multi-brand applications for powertrains, and it has already proposed and tasted the sweetness: reducing R&D cycles and risks, and significantly reducing Redundancy on the models. In fact, reducing the cost itself increases the reliability and safety of the vehicle.

In terms of battery module design, Volkswagen has adopted the same idea: to create a battery module modular platform. In other words, there is no need to design modules for every model. “Heinz-Jakob Neusser, a member of the board of directors of the Volkswagen Group responsible for research and development, revealed to the media that although battery models vary in size, unified battery cells can use different package quantities and methods to meet various needs. The goal is to reduce the battery cost by 66% through simplified battery cell design.” This is a matter of several years ago, and we are not tangling whether this goal has been achieved, but the modular approach is correct.

The new modularity, in addition to the modularization of the structural angle, is aimed at reducing costs and increasing reliability, and more importantly, it requires modularization in terms of functional control. Emphasis on the independence and completeness of the function. For example, the module's terminal acquisition, charge and discharge management, safety management, and thermal functions are all integrated. In a narrow sense, the electronic components of the battery need to have the function of the battery management module BCU in addition to the acquisition and equalization functions. Use Internet communications to more effectively monitor battery safety.

Modularization not only achieves a high degree of unity of structure and function, but at the same time, when the module becomes the concept of “energy block”, it can completely select the power according to the demand of the vehicle. If the new four-engined vehicles are equipped with flexible, safe and lightweight energy blocks, the power source will no longer be a bottleneck that is of concern.

2. Cell core connection technology revolution, opening up the vertical "recycling and recycling value chain"

The connection of the battery cores, from the initial bolting to the current welding process, has improved the stability, consistency, and longevity of its advantages, the structure volume has also become smaller, and the internal resistance has been greatly reduced. Core power can be maximally released. The disadvantage is that the lithium ion battery's unique step-by-step utilization and recycling applications have caused trouble and increased costs. Welding process, in the production of front-end, requires special equipment, tooling molds to complete; back-end maintenance, use of ladders, terminal dismantling, but also very inconvenient. At present, the use of links, the general dismantling to the end of the module. Repeated use is not thorough. Therefore, although welding is the main process of existing cell connection and grouping, from the value chain analysis, the welding process is only a one-way process, hindering the reuse of lithium-ion batteries.

In recent years, some manufacturers are trying new connection technologies. This innovation is worthy of recognition. The random combination of the batteries is not only a big cost reduction, but more importantly, it promotes the module's modularization and standardization process. It is also in line with the thinking of the new four development.

3, modular voltage standard platform, open up multi-purpose

The development trend of the new four modernizations, from the perspective of sharing in a broad sense, also applies to parts-level needs. We imagine that if the power battery module is also suitable for the 48V low-voltage platform of the future vehicle; the same 72V module that can be retired from the passenger vehicle can be applied to the low-speed electric vehicle, etc. because of the independence and standardization of the modularization and the application scope. Will greatly increase. At the same time, it also facilitates the deep plowing of products in terms of safety and other performance. Achieve the sharing of power battery modular units and open up more application fields.

summary

Power battery as a power source, in the aspect of technological progress recognition, from the initial "cell is all", rose to PACK's system integration design concept. However, with the implementation of backfilling, in the face of inherent cost pressures, safety and reliability, the development of power battery innovation is imminent. At the same time, the proposal of the new four-car automobile needs better matching of batteries. There are many ways on the road to battery innovation. It is also necessary to draw on the train of thought for the development of traditional vehicles. It is also necessary to develop new innovative thinking.