Replacing Graphite with Silicon as an anode in lithium-ion batteries

Replacing Graphite with Silicon as an anode in lithium-ion batteries
by Team HPQ

Energy storage technology is critically important in contemporary economies, as the global demand for energy continues to increase.

Currently, lithium-ion technology is the most ubiquitous battery technology on a global scale. These batteries are widely used in smaller applications which ultimately makes them dominate the portable storage market.

On another hand, for large scale applications like in the electric car battery, and utility-scale energy storage industries, adoption has been slow and somewhat challenging due to the technology’s restrictive capacities.

Innovation centering around the use of silicon in battery anodes has sparked new potentialities for lithium-ion batteries. Lithium-ion batteries are currently designed using graphite anodes, as graphite exhibits several optimal qualities, such as its structural stability and low electrochemical reactivity.

Graphite anodes are consistent performers; however, their limited energy capacity makes them ill-suited for tackling global electrification. Silicon anodes, on the other hand, absorb more lithium than their graphite counterparts; this offers a substantial improvement in battery efficiency.

Atomically speaking, substituting graphite for silicon as the primary material in the lithium-ion anode would improve its capacity for taking in ions because each silicon atom can accept up to four lithium ions, while in graphite anodes, six carbon atoms take in just one lithium.

Replacing Graphite with Silicon also allows for the manufacturing of smaller size batteries for electronic devices and electric cars, and presents a potential to increase battery charge by ten times.

Although the storage capacity of silicon anodes is impressive, critics will mention wear and tear as a drawback to its commercialization. See, lithium-ion batteries contract and expand as they release and absorb lithium ions. This cycle reduces the life span of silicon anode batteries as a result of wear and tear.

But not to worry as a recent study from the University of Alberta solves this issue.

The study demonstrated significant innovation in improving the longevity of silicon anodes in lithium-ion batteries. The findings indicated that as the particles get smaller, [they] are better able to manage the strain that occurs as the silicon breathes. In other words, the smaller the silicon particles, the less wear and tear occur.

Other studies have corroborated this, stating that silicon nanoparticles (Si-NPs) smaller than 150 nm avoid the formation of fissures upon the first lithiation, therefore reducing the mechanical strain and preventing deformation and cracking of the electrodes

Improving the life span of silicon anodes is critical in expanding the possibilities of battery storage, and the ensuing commercialization of its applications that could reshape the global economy.

charging-ev

Battery electric vehicles (BEVs) are powered with electricity stored in a battery pack, which in turn operates an electric motor and turns the wheels. When depleted, the batteries are recharged using grid electricity, which can be done via a wall socket or charging station

The next step towards commercializing silicon anode lithium-ion batteries lies with refinement. By simplifying and standardizing the process used to convert silicon into nano-sized particles, the market potential of silicon anode batteries (and the products which could potentially utilize them) could be vastly expanded.

HPQ Silicon Resources is developing the PUREVAP™ Quartz Reduction Reactor (QRR) Project in partnership with Pyrogenesis Canada Inc. The project is a new Carbothermic process (patent pending) that allows the transformation and purification of quartz (SiO2) into high purity silicon metal (4N+ Si) in one step.

After completing numerous milestones since its inception in 2015, HPQ is about to start its 50 Ton per Year Gen3 PUREVAP™ QRR pilot plant. This process will demonstrate the company’s ability to produce high purity Silicon at competitive costs, and produce value-added Silicon Materials, qualifying and selling products to potential customers.

Electric transportation, in particular, is an industry that relies massively on battery performance. It can practically be guaranteed that electric vehicles (EVs) will gain a significant boost in market competitiveness once battery storage is expanded, and HPQ’s PUREVAP™ Quartz Reduction Reactor (QRR) Project has an important role to play in this equation.

The refinement of silicon anode lithium-ion batteries into commercially viable products is an exhilarating prospect, as it will help usher in the age of low carbon, and an electrified global economy.

Since 2015 HPQ Silicon Resources INC. has been working on developing a new process for producing high-grade Silicon metal (Si) for the manufacture of solar cells.