SMM News, April 17th:

Recently, SAIC's smart car brand Nezha officially launched its new all-electric model Nezha L6, announcing that the "first-generation Photon solid-state battery" equipped on the vehicle is the "industry's first 900V high-voltage ultra-fast-charging solid-state battery". This has quickly made solid-state batteries the focus of public attention and sparked widespread market interest.

Shortly after, GAC Group unveiled a high-safety, high-capacity all-solid-state power battery at the 2024 GAC Technology Day. The group stated that the all-solid-state battery has three core advantages: ultra-high energy density, ultra-high safety, and large-capacity all-solid-state cells. It is expected to be equipped on the Haope model in 2026, further igniting the "solid-state battery" spark in the market.

**Solid-State Batteries: The Determined Future**

Solid-state batteries, which replace the liquid electrolyte in traditional lithium-ion batteries with a solid-state electrolyte, possess multiple advantages such as strong safety performance, high energy density, wide operating temperature range, and long cycle life. Their significant improvements in safety and driving range are not only key industry pain points that major new energy vehicle companies are eager to solve, but also directly address consumers' primary concerns about electric vehicles. Therefore, the R&D and application of solid-state batteries have already been prioritized by relevant enterprises.

However, due to technology and cost constraints, solid-state batteries are still some distance from actual application: the price of solid-state electrolytes is high, and a high-pressure environment is required to ensure lithium ion diffusion; the solid form also leads to severe lithium expansion during charging and discharging, which greatly affects battery cycling... Zeng Yuqun, the founder of CATL, stated: "CATL fully supports solid-state battery technology, and has been working on it for 10 years, but there are still many obstacles."

In fact, the solid-state batteries currently launched by major manufacturers are mostly semi-solid-state batteries, still some distance from the actual solid-state batteries. However, even in the semi-solid-state form, the battery performance is still extremely strong. Of course, various companies also have technological breakthroughs and product outputs for all-solid-state batteries. As the actual mass production and application scale expands in the future, it can be said that solid-state batteries, as the "ultimate solution" of lithium-ion battery technology, have a determined future in development.

**Anode: The Key to Solid-State Battery Energy Density**

Looking at the parameters of solid-state batteries recently released by the market, it is not difficult to find that their capacity is significantly higher than that of liquid lithium-ion batteries, greatly improving vehicle driving range. One of the important factors affecting battery capacity is the choice of anode material.

The current mainstream choice in the lithium-ion market is graphite anode. Graphite anode technology is relatively mature, and its capacity is close to the theoretical capacity of 372mAh/g. Therefore, there is limited room for significant breakthroughs in energy density, and enterprises have shifted their research and development focus more towards fast charging and cycle life performance.

Silicon-based anode, with a theoretical specific capacity of 4200mAh/g significantly higher than graphite, is considered an excellent next-generation anode material. In addition to the capacity advantage, silicon-based anode has a relatively low lithium deintercalation potential (~0.4V vs. Li/Li+), which can avoid the lithium plating phenomenon during charging, while the voltage platform of graphite anode is close to the lithium deposition potential, easily leading to the formation of lithium dendrites that can penetrate the separator and cause battery short circuits, posing a safety threat. Therefore, silicon-based anode also has safety advantages.

The main challenge of silicon-based anode is its significant volume expansion during charging and discharging. Therefore, current silicon-based anodes are often blended with graphite materials, which can improve capacity while ensuring the performance of other key parameters.

In solid-state batteries, silicon-based anode has also become the most suitable choice. Nezha's solid-state battery supplier Qingtao Energy has signed a strategic cooperation agreement with anode company Xiangfenghua on the key technology research and development, as well as supply, of high-capacity anode materials for solid-state/semi-solid-state batteries. GAC's all-solid-state battery uses the third-generation sponge silicon composite anode material. Leading domestic anode companies such as BYD, Shanshan, and Zichen are also accelerating the R&D and testing of silicon-based anodes.

The current price of silicon-based anode is relatively high. For example, the market price of CVD-prepared silicon-carbon anode can reach above 770,000 yuan/ton, with profit margins far exceeding graphite anode. At the same time, due to the impact of R&D progress, the actual application of silicon-based anode is currently limited, but its future market share is expected to be large.

Although solid-state batteries are still in the initial stage, they represent a shot in the arm for the anode industry. Accompanying the technological breakthroughs and the growth of downstream demand, silicon-based anode will bring new opportunities and markets for anode companies, driving the further development of the entire industry.