Higher capacity silicon-anode lithium-ion batteries make data-driven insights more important than ever
The world is demanding more powerful, longer-lasting batteries for electronics and vehicles. Many new battery technologies and chemistries are rising to the challenge, from sodium-ion to solid state to lithium-ion batteries with silicon anodes — the market for which is projected to grow by more than 60% over the next 10 years.
The momentum behind silicon-anode batteries is in large part driven by their ability to store more energy than lithium-ion batteries of equivalent mass and volume. However, their increased energy density could also pose new, different, and potentially more dangerous risks in the event of a failure.
While many startup companies and major manufacturers are ramping up silicon anode production, ensuring these batteries can hold up to real-world use is paramount. Gaining and maintaining market share for this emerging technology will take special focus on developing effective safety, reliability, and long-term performance testing.
Capturing benefits, managing risks
Lithium-ion battery chemistry has remained relatively unchanged for decades. In a lithium-ion battery, lithium ions flow between the graphite anode and the transition metal oxide cathode. Graphite is a configuration of carbon atoms in an intricate yet durable honeycomb structure that is resistant to swelling and physical damage, resulting in an anode that is strong and relatively stable during use. This durability is why graphite has been used in commercial lithium-ion batteries since the 1980s.
However, graphite can only hold so many lithium ions: it takes six carbon atoms in a graphite configuration to hold a single lithium ion, which limits the overall energy density of lithium-ion batteries.
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In comparison, Silicon can hold 10 times more lithium ions on a per-mass basis than graphite. Silicon anodes may also reduce charge times and increase power output across numerous applications, but there is a critical problem: swelling.
"No energy storage system is flawless, but companies can reduce risk and help avoid loss and liability by developing battery testing procedures that go beyond pass/fail results."
Silicon expands to more than three times its original volume when absorbing lithium ions. This swelling is why silicon anodes have remained impractical for many years. Only recently have some companies started developing engineered solutions to control the problem. In some instances, battery firms have completely redesigned the anode using proprietary materials or novel configurations of existing materials, including success in lab testing and plans to move forward with large-scale manufacturing. However, since most of the technologies are still emerging, many have not been subjected to extensive real-world use, increasing the importance of thorough testing for this new chemistry.
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