Unveiling the CATL solid-state battery route
2024-04-30 15:07

TrendForce has learned that at the CIBF2024 Advanced Battery Frontier Technology Symposium on April 28, Wu Kai, Chief Scientist of CATL, announced for the first time the mass production schedule of all-solid-state batteries.

According to Wu Kai, if technology and manufacturing maturity are used as an evaluation system (scored on a scale of 1-9), the development of CATL's all-solid-state battery is currently at a 4-point level. CATL plans to reach a level of 7-8 points by 2027, which means that by then all-solid-state batteries can be produced in small batches, but there will be some problems for mass production such as cost.

Wu Kai said that at present, the energy density of liquid lithium batteries can reach 350Wh/Kg, but it is difficult to increase it further. However, all-solid-state batteries have excellent performance in energy density and safety, with great potential to increase.

CATL's solid-state battery route

According to TrendForce, the current solid-state battery technology is divided into four main technology paths: oxide, polymer, halide, and sulfide solid-state batteries, depending on the electrolyte.

According to Kai Wu's speech, CATL’s battery is sulfide solid-state battery.

In order to solve the problem of the environmental stability of sulfide electrolytes, CATL provided two solutions. The first one is to coat the design with a reversible amphiphilic molecular hydrophobic layer to improve air stability, and the second is to develop new synthetic routes and materials with low lithium content to reduce costs.

CATL also adopted a dual strategy for the problem of lithium metal anode:

On the one hand, the phase change self-filling technology is used to strengthen the electrolyte structure and inhibit the growth of lithium dendrites. On the other hand, the interface ion transport "highway" is constructed through the design of the lithiphilic interface layer, so as to give full play to the high performance of the lithium metal anode.

In terms of cathode materials, CATL has developed a multi-layer full-coating technology for mono crystal cathode to enhance the stability of the interface structure, and combined with multi-functional composite adhesives to build an efficient electrode piece conductive network.

In terms of manufacturing technology, CATL has provided the dry/wet electrode piece preparation and integrated battery molding process scheme, and has established a 10Ah all-solid-state battery verification platform.

CATL's solid-state battery layout

Although there are few reports about CATL's progress in the field of solid-state batteries, in fact, the company has already laid out and invested in this field.

In April 2023, CATL released condensed matter batteries, which has a single energy density of up to 500Wh/kg.  Semi-solid colloidal electrolyte is used in this battery, which is a technical route between liquid batteries and solid-state batteries.

In December 2023, CATL said that the company is committed to solving various engineering and technical problems of solid-state batteries and has a large number of technical reserves. At present, the company's condensed matter batteries has high specific energy and safety, and can be mass produced faster than solid-state batteries.

At the performance interpretation meeting held on the evening of March 15 this year, Zeng Yuqun, chairman of CATL, said that the company attaches great importance to solid-state batteries which has been laying out for many years, and CATL has recently increased a lot of investment.

Zeng Yuqun said that there are three technical routes for solid-state batteries, including namely oxide, sulfide, and polymer. But there are still many basic scientific problems to be solved, such as the difference between the ion diffusion rate in most solid-state electrolytes and liquid electrolytes.

In terms of patented technology, CATL also has a layout. The company announced on April 9 that it has obtained an invention patent authorization, with the patent name of "binder, preparation method, anode slurry, negative electrode piece, solid-state battery and electrical device". The publication number of this technology is CN117165222B and the application date is November 2, 2023.

Tags:battery , CATL