Solid-state Batteries Are Beginning To Emerge

- Sep 02, 2019-

Technology has always been spiraling, and breakthroughs are not overnight.

On August 2, Volkswagen Group CEO Herbert Diss claimed that Volkswagen Group will build a solid state battery in Europe and is expected to achieve mass production between 2024 and 2025. Recently, the US Department of Energy directly allocated 9.1 million yuan. The US dollar was used by GM for R&D, and it indicated that 2 million US dollars should be related to solid-state battery development. On August 22, Weilai Automobile and Huineng Technology strategic cooperation agreement, the two parties will jointly build a sample of Huineng MAB solid-state battery pack. car. In the future, the two sides will further cooperate on the production of solid-state batteries.

A series of signs indicate that domestic and foreign automakers are beginning to invest more in solid-state batteries. The root cause is the limitations of lithium battery technology, and the profitability of solid-state batteries is huge.

First, the technical limitations of lithium battery

According to data from the China Automobile Association, China’s new energy passenger vehicles sold 67,000 units in July, down 51.4% from the previous month and down 9.4% year-on-year.

The sales of new energy vehicles in China were cold in July. On the surface, they were affected by the decline in policy subsidies. In fact, they are still the core lithium-ion battery technology limitations, the price/performance ratio is not high enough, the safety is questioned, and the product advantages are not obvious enough.

Therefore, in order to maintain sales, we will live better in the era of non-subsidy. Lithium-ion batteries must reduce costs and achieve high safety, high energy density, light weight and other goals.

As far as the current situation is concerned, the cathode material has turned to high-nickel ternary development; while the anode material is concentrated in graphite materials, it also transitions to the silicon-carbon anode.

However, even if the performance of the positive and negative materials is good enough, the energy density will stop at 400 Wh/kg, which is determined by the theoretical capacity of the positive and negative materials.

On the contrary, the solid-state battery's alkali metal electrode can increase the energy density and prolong the service life, while the solid electrolyte has high transmission efficiency, does not cause overheating and explosion, and has sufficient safety.

Second, the main performance of safety

Despite the cold sales in July this year, overall, the sales of new energy vehicles are still growing year by year.

New energy vehicles have security incidents, of which battery self-ignition accounts for 31%, which makes potential consumers worry and affects the development of new energy vehicles.

The safety of new energy vehicles affects the hearts of market consumers, and it is easy to have a negative impact. After all, no one is willing to take life to buy a car.

The use of solid electrolytes will effectively reduce the risk of spontaneous combustion of the battery.

Nowadays, car companies in various countries are vigorously developing solid-state battery technology. To some extent, they are trying to use the "moat" of high security to intercept competitors and occupy more markets.

Third, solid battery development route

Solid-state batteries use non-flammable solid electrolytes to replace flammable organic liquid electrolytes, which will greatly improve the safety of the battery system, and at the same time better adapt to high-energy positive and negative electrodes and reduce system weight, achieving simultaneous energy density enhancement. It can be said that the above two technical limitations of lithium ion batteries are well compensated.

Among various new battery systems, solid-state batteries are the next-generation technology that is closest to industrialization, which has become the consensus of the industry and the scientific community.

The development of solid-state batteries is essentially to reduce the use of liquid electrolytes, from semi-solid to quasi-solid, and eventually to liquid-free all-solid-state batteries.

Solid-state batteries have high electrical conductivity, high mechanical strength and high energy density. However, there are still research difficulties in the interface between electrodes and electrolytes. The problems of large-scale industrialization and cost reduction remain to be overcome. But solid-state batteries have taken the pace of industrialization.

On the positive side, there is a corresponding technical accumulation and industrial resources in the domestic lithium battery field, which can help realize a small number of commercialized solid-state battery products. The downside is that the cost and application areas are limited, and the traditional lithium battery has not formed a sufficient competitive advantage.

Fourth, solid battery application

Solid-state batteries are the inevitable result of the development of lithium-ion battery technology, and can completely replace existing lithium-ion products in specific application fields.

Solid-state batteries are small in size and are expected to take the lead in safety and flexibility. They are preferred to expand in micro-cells with low cost sensitivity, such as RFID, implantable medical devices, and wireless sensors.

Then, with the maturity of technology and products, the cost of solid-state lithium batteries is reduced. Together with the high energy density and small volume, it can be used in domestic passenger cars and buses with short strokes and used as power batteries.

In the end, it entered the electric vehicle and energy storage market on a large scale, and penetrated from high-end brands to achieve a comprehensive outbreak of downstream demand.

Breakthroughs in solid-state battery technology will bring huge benefits to many applications, including new energy vehicles, and form at least a trillion-scale market.

Solid-state batteries are just beginning to emerge, and the road ahead will take time to hone.