Prepare for New Advances in Battery Technology in 2021

Ever since Volta discovered in 1800 that certain fluids would generate a flow of electrical power as part of a chemical reaction, the age of batteries was born. Little did Volta know that he would have a unit named after him (probably one of the greatest honors a scientist can receive), and his discovery would underlie all mobile technology in use today. Fast-forward to today, and the fundamental structure of batteries still matches that used in the Daniell cell, first introduced in 1836.

Today, the conversation around batteries has focused on their use as enablers for other technologies, such as firming up renewable energy sources and electric vehicles. Despite the historical and recent advances in battery technology, many challenges still remain in making batteries more environmentally friendly, cheaper, and safer at high discharge. However, many companies are working on developing new material platforms for batteries without making major changes to battery chemistry.

Today’s Battery Challenges

The challenges present in today’s batteries and power storage systems center around safety and environmental friendliness. The current best-in-class battery chemistry for power delivery is Li-ion, which also has the greatest safety hazards, yet it is still comparable to nickel metal chemistry in terms of capacity. Since lithium chemistry already offers some advantages in terms of power delivery, it has been the focus of further development and improvements. Despite its advantages, Li-ion batteries have their drawbacks:

• Lifetime: Here, we’re referring to the overall useful lifetime of the battery, rather than charge capacity. The lifetime of Li-ion batteries is greatly affected by the depth of charge/discharge, charge/discharge rate, number of charging cycles, operating temperature, and the geometry of the cell. 

• Charging/discharging safety: Li-ion batteries require a power monitoring and protection circuit to prevent overheating and overcharging. Similarly, during a discharge cycle, the protection circuit limits the discharge rate to keep the cell’s voltage from dropping too low. 

• Form factor vs. capacity: Although smartphones have gotten flatter, the battery size has gotten larger to provide higher capacity. As a result, more components are being consolidated into SoCs and onto flex boards to make room for larger batteries. It’s desirable to increase capacity without increasing the physical size of the battery.

• Recyclability: The rush of new electric vehicles projected to come online in the near future raises serious concerns around end-of-life for Li-ion batteries. Newer materials and battery structures may be required to reduce the energy required to recycle an Li-ion battery.

Li-ion polymer battery packs provide a flexible form factor with competitive capacity and charge/discharge characteristics. Newer materials can enable greater safety with higher power delivery and capacity.

Advances in Battery Technology Start With Materials

The most recent advances in battery technology focused on moving away from alkaline chemistry and nickel metal chemistry into lithium chemistry. Upcoming advances in battery technology are primarily focused on materials that address the challenges listed above, and not necessarily on the external power management methods and components. If you look at the battery industry, there are two areas where companies are innovating with new materials: the electrodes and electrolytes.

Semi-porous Anode/Cathode Materials

Porous materials provide some unique advantages in battery anode and cathode materials so long as they can provide low resistance and high thermal conductivity, the latter of which addresses a primary safety concern in high power/high capacity batteries for electric vehicles. One example anode material is graphite coated with carbon nanoribbons, which can be easily incorporated into existing anodes for Li-ion batteries. The porous nature of this particular material provides a larger active surface area, which allows for greater flux of charge into/out of the anode terminal and greater Li-ion storage than a solid graphite electrode.

All Solid-state Batteries

Solid-state batteries are of interest as they allow a flammable liquid electrolyte to be replaced with a non-flammable solid electrolyte. Lithium is also of interest here as this would allow the chemistry of these systems to be preserved. Earlier this year, Samsung announced development of an all solid-state Li-ion battery platform. Samsung’s battery used a silver-carbon composite material as the anode to suppress dendritic growth from a metal anode. These batteries are not commercially available just yet, although the use of solid electrolytes is known to be safer compared to the liquid electrolytes used in today’s commercial batteries.

Companies like Toyota, Nissan, and VW-backed Quantumscape are building their own solid-state battery platforms for electric vehicles. Once commercialized, these platforms could be game-changers for electric vehicles as they could offer longer range in a smaller package without longer charging time. This puts the focus back on board designers to build the best management systems to support vehicle battery platforms that are safe and have the highest possible efficiency.

Separator Materials

This is still an area of scientific research as separator membranes need to be highly durable and porous. Polyolefin is used as the separator in commercial Li-ion batteries, and any new separator material would need to allow high ion exchange without generating excess heat. It also needs to have high mechanical strength and chemical stability. Researchers are still investigating new separator materials to meet these demands without incurring major changes to the battery chemistry or electrical characteristics.

Some examples of separator membrane materials. [Source]

Why the focus on using the same material platforms that have already been commercialized? The current chemistry used in industry-leading batteries (alkaline or lithium chemistry) has been thoroughly studied and qualified for safety, both by government regulators and the battery industry itself. Once you change the class of materials, you also change the chemistry, and the extensive evaluation process starts all over again. Therefore, many in the industry are hesitant to move away from existing materials platforms; the investment and risks are just too high.

As more advances in battery technology lead to new products, we’ll be here to keep you informed with the latest news and analysis. When you’re looking for a new long-lasting, high-capacity battery and power management components for your next system, use the advanced search and filtration features in Octopart. You’ll have access to an extensive search engine with distributor data and parts specifications, all of which is accessible in a user-friendly interface. Take a look at our power management integrated circuits page to find the components you need.

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