IDTechEx forecast the market for silicon anodes to exceed US$15 billion by 2035, driven by demand for higher energy density and faster charging batteries and growing interest and investment into silicon anode materials, technologies, and production capacity. This report provides in-depth analysis and discussion of silicon anode technologies, the silicon anode market, key players and start-ups, provides a production outlook, and forecasts by region and application by GWh, kt and US$.

 

Market landscape

The battery electric car market represents the largest addressable market for silicon anodes given the underlying size of the battery market for electric cars as well as their need for higher energy density and faster charging battery technologies. Silicon oxides are already being incorporated at low weight percentages in some BEV models. However, by weight, silicon anode materials represent only approximately 1% of the market. Driven by increasing demand for higher performance Li-ion batteries and improvements in silicon anode technology, the share of silicon anode material is expected to increase rapidly by both kt and GWh.

The silicon anode market is expanding with 30+ start-ups identified in the report as well as increasing involvement from established materials companies aiming to enter, expand and future-proof their presence in the battery market. Production capacity for silicon-based anode materials is expected to grow rapidly over the next 5 years, while funding into silicon anode start-ups is estimated to have exceeded US$4.5 billion 2024 with this capital making its way to constructing commercial scale production. The report details key silicon anode developers and companies, the current state of the market, provides an outlook for silicon anode production capacity.

Technologies

Silicon has long offered the potential for higher energy density batteries due to its capacity of 3600 mAh/g compared to the 360-370 mAh/g available from graphite anodes. Improvements to other characteristics, including fast charging are also possible with the use of silicon anodes. However, silicon expands by up to 300% when lithiated, causing numerous issues, from electrolyte and lithium consumption, to loss of electrical and ionic conductivity, which ultimately leads to low cycle life. To overcome these issues, numerous technologies and solutions have been under development. For example, the replacement of graphite with a small amount of silicon oxide can minimize these detrimental effects and has to date been the only solution to gain widespread traction, but using low amounts of silicon also reduces the performance benefits on offer from silicon.

 

Attempts are underway to develop and commercialize materials that enable higher percentages of silicon-based anode material to be used in order to increase energy density and enhance fast charge capability. Materials and technologies being developed include silicon-carbon composites, silicon-graphite composites, silicon oxides, pure silicon materials and silicon nanostructures. The different solutions being developed can offer distinct advantages and disadvantages. For example, silicon-carbon composites have attracted significant interest with materials typically incorporating silicon into porous carbon structures via a chemical vapor deposition (CVD) process. The porous carbon structure provides space for the volume expansion of silicon whilst providing electrical conductivity but controlling the deposition process can be difficult, production can be expensive, and access to silane gas needs to be ensured. This report provides analysis and discussion of the silicon anode technologies being developed, commercialized, and produced, by major players in the silicon anode market.

 

Performance and cost

The current iteration of Li-ion batteries are starting to reach their performance limits. Shifts in electrode materials and cell designs are necessary to move beyond energy densities of around 650 Wh/l exhibited by state-of-the-art cells based on graphite and high-nickel NMC/NCA. Moving toward anode compositions with even modest quantities of silicon can improve energy density significantly, while high-silicon or silicon-dominant anodes could enable energy densities above 1000 Wh/l. Rate capability and fast-charge capability can also be enhanced through the use of silicon with numerous players demonstrating improved fast charge capability and low-temperature performance. Importantly, cycle lives toward and in excess of 1000 cycles are being reported by various companies developing different silicon anode solutions. While progress is being made, challenges regarding calendar life or cell swelling and breathing remain.

 

Cost remains a critical factor in determining the outlook for silicon anode materials. While companies are targeting cost parity or even savings, compared to graphite on a US$/kWh level, silicon anode material is likely to come at a price premium in the short-term. The impact on cell level material costs is then dependent on many factors, including cell design and chemistry, the price and performance of silicon anode materials used, and the price of graphite being replaced, amongst other factors.

The report provides an overview of the latest developments to silicon anode technologies, including to Si-C and Si-Gr composites, silicon oxides, and pure silicon materials, and covers the start-ups, pure-play, and established companies active in developing and producing silicon anode materials. Forecasts for the silicon anode market are provided by silicon technology (silicon-additive, mid-silicon, high-silicon), application (battery electric cars, commercial EVs, and electronic devices), and region (China, US, Europe, global) by GWh, kt and US$.