Recently, Sun Huajun, CTO of BYD Lithium Battery Co., Ltd., revealed that BYD will launch all-solid-state battery batch demonstration vehicle installation applications around 2027, and achieve large-scale vehicle installation after 2030.

One of the key points is that BYD will have offline 60ah all-solid-state battery in 2024.

Sun Huajun also said that liquid ternary lithium batteries and solid ternary lithium batteries can theoretically achieve the same price for solid and liquid. Sun Huajun emphasized that "product strength must be viewed comprehensively. Whether it is battery life or charging for electric vehicles, power performance may not be a big issue. The core is charging. Increasing the proportion of active materials and significantly reducing the amount of electrolyte are factors that ensure low cost from the design point of view."

It is understood that in the selection of solid-state battery technology route, BYD adopts a combination of high nickel ternary (single crystal) + silicon-based negative electrode (low expansion) + sulfide electrolyte (complex halide), which is significantly different from SAIC's polymer route and Toyota's oxide route.

Data shows that BYD 60ah’s all-solid-state battery has an energy density of 400Wh/kg, which is twice that of existing liquid batteries. The combination of -40°C low-temperature starting capability and 5C ultra-fast charging (replenishing 80% of the battery in 10 minutes) has set a new industry record.

BYD has also made key progress in the issues of interface impedance control and low-temperature performance degradation that are commonly faced by the industry. It uses composite halide electrolyte technology to increase the discharge efficiency in a -30°C environment to 85%, which is 15 percentage points higher than competing products from Japan and South Korea.

In the 100GWh production capacity plan of BYD's Chongqing Bishan base, the first phase of the 20GWh production line is planned to be put into operation in 2026, with the goal of reducing the cost of all-solid-state batteries to US$70/kWh, which is the same as the current liquid battery.

It is worth mentioning that previous news mentioned that in addition to BYD models’ own use, BYD’s all-solid-state batteries will also be supplied to other companies.

In the second half of 2024, information from the State Intellectual Property Office shows that BYD has a number of all-solid-state battery patents disclosed.

For example: a BYD patent titled "All-solid-state batteries, battery packs and electrical equipment", the public number is CN 118748295 A. The inventors are Shi Hongbing, Wang Guoshuai, Guo Zizhu, You Maolin, and Shi Zhuo. The application publication date is October 8, 2024, and the application date is August 7, 2024.

The abstract shows that the patented all-solid-state battery includes negative electrode sheets and positive electrode sheets arranged in a staggered stack. There is a solid electrolyte layer between the negative electrode sheets and the positive electrode sheets, and the outermost is the negative electrode sheet. The outermost negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer and a ceramic layer respectively disposed on both sides of the negative electrode current collector. The ceramic layer is located on a side surface of the negative electrode current collector facing away from the positive electrode sheet.

According to the instructions, the ceramic layer of the patented all-solid-state battery meets at least one of the four conditions of Mohs hardness 3~10, Poisson's ratio 0.1~0.5, density 50%~90%, elastic modulus 2~10GPa, and the thickness of the ceramic layer is 30μm~150μm.