The future of electric vehicles will start with a revolution in battery technology

When it comes to the future of electric vehicles, the key is to reduce battery costs. Compared with basic battery materials, the revolution is difficult. Power battery CTP seems to be a shortcut. This is why. According to public information, after my country’s new energy vehicle subsidy fell in June, the sales of new energy vehicles plummeted for three consecutive months, of which BYD fell the most by 31%. For fuel vehicles, the cost of power battery is the killer, because its cost ratio in vehicle manufacturing is as low as 10% and as high as 40%. The proportion of domestic vehicles is much higher than that of imported vehicles.

As we all know, ternary lithium batteries and lithium iron phosphate batteries are the two current commercial batteries. Among them, lithium iron phosphate batteries are used in the field of electric passenger vehicles with high safety, and ternary lithium batteries are favored by electric passenger vehicles because of their high energy storage density. At the same time, under the guidance of the new energy vehicle subsidy to the direction of high battery life, NCA811 and NCM811 high-nickel ternary lithium batteries have gradually become the mainstream of the market.

It is reported that although the high-nickel ternary lithium battery is far ahead in energy storage density, and at the same time reduces the amount of cobalt metal used to achieve the goal of reducing battery manufacturing costs, it will bring the adverse consequences of thermal runaway temperature reduction, resulting in electric vehicles in the It is easy to spontaneously ignite under fast charging and intense driving conditions, which brings safety hazards to the car owner.

As a result, the revolution of the basic materials of power batteries has become the key to the development of electric vehicles. Among them, solid-state lithium batteries have become the next generation batteries. my country has formulated a perfect development route. Among them, high-nickel positive electrodes + quasi-solid electrolytes + silicon carbon will be used before 2020. The anode can achieve 300 Wh/Kg, the lithium-rich cathode + all-solid electrolyte + silicon carbon/lithium metal anode battery can achieve 400 Wh/Kg before 2025, and the fuel/lithium-sulfur/air battery can achieve 500 Wh/Kg before 2030 .

In fact, although solid-state lithium batteries have advantages in energy storage density, safety of use and manufacturing costs, there are actually three technical bottlenecks that make it difficult to achieve commercial applications. The first is the low ionic conductivity of the solid electrolyte, and the second The mechanical properties of the solid electrolyte are poor, and the interface between the solid electrode and the solid electrolyte is poor, which will affect the cycle life and rate performance of the solid-state lithium battery.

Industry insiders pointed out that compared with the difficult revolution of battery basic materials, there is actually a shortcut to reduce battery manufacturing costs. It is a CTP battery production method that combines battery cell manufacturing and PACK manufacturing. , according to the CTP technical data of CATL, not only can the volume utilization rate of the battery pack be increased by 15-20%, the number of battery pack components can be reduced by 40%, the production efficiency can be increased by 50%, and the energy density of the battery pack can be increased by 10%- 15%, reaching 200WH/kg, so as to reduce the cost of battery manufacturing.

However, there are also hidden dangers in CTP eliminating the module, because the battery module not only supports, fixes and protects the cell, but also protects it from deformation that damages performance, controls the temperature of the cell, and avoids the spread of thermal runaway. Once the battery module is eliminated, the battery pack is directly composed of cells, which will greatly reduce the difficulty of battery reliability and battery safety management.

At the same time, CTP battery packs put forward higher requirements on the consistency of battery products. According to industry technicians, the use of CTP will limit the flexibility of battery development in the future, because once it is finalized, the PACK cannot be significantly changed. Changes will inevitably lead to increased costs. To match a new car, it is necessary to do a module experiment and a PACK experiment again. However, this is the opportunity for the unification of electric vehicle industry standards and represents the future development direction.