Paraclete Energy this week announced the launch of SILO Silicon, a silicon anode material technology that it says will transform the lithium-ion battery market, particularly for the electric vehicle (EV) sector. The Chelsea, MI-based company says that the polymer matrix architecture enables industry-leading silicon concentration, delivering energy densities of up to 300% that of traditional graphite anodes and outperforming competing silicon anode technologies by over 200%. The breakthrough is said to result in significantly increased battery capacity, allowing EVs to travel significantly longer distances on a single charge.

“SILO Silicon is a game-changer for the electric vehicle industry,” said Jeff Norris, CEO of Paraclete Energy. “This technology directly addresses the critical needs of the market, offering longer range, faster charging, and lower costs—all essential factors in accelerating the adoption of electric vehicles.”

Results from an Argonne National Laboratory study on extreme fast charging released in March 2023 concluded that the addition of Paraclete Energy’s silicon technology increases rate capability from 1C to 8C and improves capacity retention in early cycles at 6C. Increasing the silicon amount in the composite anode improved the rate capabilities, specific capacity, and cyclability of cells. The addition of silicon was shown to reduce the possibility of lithium plating when a thin electrode was used to maintain a similar capacity compared to that of the graphite-only electrode.

It’s significant that the Paraclete SM-Silicon/3590 product used in the Argonne study did not include the company’s new SILO Silicon technology, which was developed to dramatically improve cycle life and stability of those powders.

As Norris explained in a recent presentation for the SM-Silicon/3590 material morphology, the SILO Architecture’s interface strength (adhesion) between the matrix and the outer shell is ensured by chemical bonding. The matrix is an ion- and electron-conductive composite that contains lithium-active particles and is engineered to withstand long-term cyclic mechanical loading due to its morphology and chemical composition. The outer shell is a continuous layer without inclusions, is ion- and electron-conductive, and reinforces the matrix material volume.

Paraclete Energy says that batteries made with SILO Silicon are 33% less expensive per kW·h than traditional carbon-based products. The company is shipping in the fourth quarter of 2024, which it says is years ahead of projected competitor projects.

Maximizing energy density has been one key area of focus in EV battery development. Optimizations in cell and battery pack designs, alongside the use of higher nickel NMC (Nickel Cobalt Manganese) and NCA (Nickel Cobalt Aluminum) cathodes, have led to steady improvement in battery energy density over the past 10-15 years.

The energy density limit from current design and material iterations has largely been maximized, according to Dr. Alex Holland, Research Director at research firm IDTechEx. However, he believes silicon is an emerging material that offers a step-change improvement in advanced lithium-ion battery prospects. His new report, “Advanced Li-ion Battery Technologies 2024-2034: Technologies, Players, Forecasts,” includes analysis on the latest in silicon anode developments and forecasts the market for silicon anode material for lithium-ion batteries to exceed $24 billion by 2034.

According to Holland, silicon has a theoretical energy-density capacity of 3600 mA·h/g at room temperature, or nearly ten times the 360 mA·h/g of graphite, which is used as the anode material in most lithium-ion batteries. By replacing graphite with silicon, cell-level energy densities of more than 400 W·h/kg and up to 1000 W·h/L become feasible, with the potential to nearly double the energy density of state-of-the-art commercial cells available in 2024. This leap in energy density could translate into EVs with twice the range or electronic devices with twice the runtime.

The benefits of silicon extend beyond capacity and energy density, said Holland. Many silicon anode companies are reporting improved power and fast-charging capabilities, increasingly important performance metrics for EVs as well as other applications such as power tools or consumer devices. Additionally, the more positive voltage of silicon compared to graphite helps reduce the risk of lithium plating and enhances battery safety, another increasingly important concern for the industry.

Currently, silicon oxides can only be used at relatively low weight percentages—less than 10%, but companies are racing to develop advanced silicon anode materials like Paraclete Energy’s that can enable higher silicon percentages in batteries. Silicon-dominant compositions remain the aim for many industry players.

The battery industry has taken notice of silicon’s potential, with IDTechEx estimating that over $4 billion of investment has gone into silicon anode startups. Some of this is now starting to go toward the expansion of manufacturing capabilities, capacities, and supply chains. Importantly, the materials and solutions being developed by some of these companies are also starting to be qualified and deployed.

Sila Nano has had materials used in the Whoop fitness wearable, Amprius has deployed batteries in drones and high-altitude pseudo satellites, while Lightning Motorcycles will offer e-motorcycles using Enevate‘s technology. Automotive OEMs have also taken note of the promise of silicon anodes, with the likes of Daimler, Porsche, and General Motors investing and partnering with silicon anode companies.

However, challenges remain for the widespread commercialization of silicon beyond its use as an additive, according to Holland. Silicon’s significant expansion during cycling can lead to issues such as excessive electrolyte consumption, electrode pulverization, and loss of electrical contact—some reasons why silicon has been used at relatively low percentages in the anode.

Significant effort has gone into overcoming these hurdles, and data being reported suggest that lives of up to 1000 cycles are attainable, making silicon broadly suitable for electric cars. Beyond cycle life, shelf life remains a concern.

In the short to medium term, silicon anode materials will most likely continue to come in at a price premium over graphite on a $/kW·h basis. This may restrict their deployment to applications where price sensitivity is lower, such as high-end EVs, military applications, or some electronic devices.