In autumn of 2021, the 26^th UN Climate Change Conference of the Parties (COP 26) met in Glasgow to work out agreements to curb greenhouse gas emissions and prevent additional climate change. COP 26 built upon the Paris Agreement to limit global warming below 2-degrees Celsius by achieving net zero carbon dioxide (CO2) emissions. These two agreements will shape how governments and industries work together to reduce climate change over the next decade.

One key agreement in the Glasgow Climate Pact calls for nations to “accelerate the development, deployment and dissemination of technologies, and the adoption of policies, to transition towards low-emission energy systems” by “rapidly scaling up the deployment of clean power generation and energy efficiency measures.” Balancing this prioritization of clean energy is a requirement to accelerate “efforts towards the phasedown of unabated coal power and phase-out of inefficient fossil fuel subsidies.” This pact is the first explicit mention of coal and fossil fuel in any U.N. climate deal.

There are many complementary strategies to reduce carbon dioxide emissions. Climate experts advise that we can maximize our efforts by focusing on adoption of renewable energy sources and greater energy efficiency of transportation. The U.N.’s economic analysis positions lithium-ion batteries as a strong mitigation strategy in the energy and transportation sectors.

While lithium-ion batteries themselves do not produce energy, they are an efficient storage solution to strengthen green energy systems. Variability is a major shortcoming of renewable solar and wind energy. Lithium-ion batteries can store energy from these sources and smooth out any gaps in energy distribution, thereby increasing green energy’s reliability and ultimate power generation capacity.

Although Sony first introduced lithium-ion batteries for consumer electronics in 1991, lithium-ion batteries are increasingly well-known for their green power in transportation. Electric passenger cars powered by li-ion batteries reduce greenhouse gas emissions by approximately two thirds compared to gasoline cars (provided that the well-to-wheel electric generation is from renewable sources). Electric cars are not the only vehicle embracing li-ion batteries, either – “bicycles, scooters, cars, buses, trucks, and even ferries” are increasingly powered by batteries, with aviation and shipping beginning to make progress as well, according to the U.N. While inner city electric busses and trucks are becoming common, long-distance, heavy electric vehicles are still out of reach. Li-ion batteries do not offer the necessary energy density to compete with gas’ cost and efficiency for long-distance freight trucks and busses.

Batteries scientists must prepare for growing demand in Li-ion batteries for electric vehicles and green energy storage. These areas require unique capabilities from Li-ion batteries which developers must consider.

Battery Requirements for Electric Vehicles (EVs) and Transportation

Which factor would make a car shopper most likely to switch from gas to electric? Vehicle manufacturers agree: runtime is the most important factor for vehicles’ lithium-ion batteries. EVs can dominate the market if they require fewer charging breaks than their fuel counterparts’ gas refills. Furthermore, li-ion batteries with long runtimes will facilitate the adoption of electric busses, cargo trucks, and airplanes.

Safety is another principal concern for electric vehicles, especially after stories of GM and Tesla battery fires spread. GM recalled their Chevy Bolt batteries after several instances of fires, but their problem is a quality control issue, not an inherent flaw in the battery design or capability. Tesla affirms that their batteries are completely safe, and the U.S. National Highway Traffic Safety Administration agreed that there was no cause for concern. Cycle life is also a top concern since consumers expect their electric cars to last for years, or even decades, like gas vehicles. Therefore, EV batteries need a high cycle life, or the ability to be discharged and recharged many times before performance decreases.

Power, or the ability to expend energy quickly, is a secondary concern for the average consumer electric car. A driver needs power to accelerate quickly and avoid an accident, but this acceleration does not require exorbitant li-ion battery power. However, racecars are a specific example of EVs that require higher power for maximum acceleration. Energy density is also not a top priority for consumer EVs since current li-ion batteries are already lightweight enough for the average car. Energy density is more important for advancements in electric aircraft. Similarly, cost is not the most important area for current innovation. Li-ion batteries for electric vehicles have already made great progress in achieving consumer-friendly costs. While cheaper costs will make EVs available to more buyers, EV producers are more concerned with battery quality and safety, even if it results in a higher price tag.

Battery Requirements for Grid Energy Storage

Although EV’s receive the most attention when it comes to lithium-ion batteries, renewable energy sources will require grid storage to smooth out the gaps as explained above. There are several battery technologies in consideration at the present, but lithium-ion battery technology is a leading contender. One reason is because green energy storage typically requires batteries to be charged and discharged every day, so cycle life is the most important factor for this application. Without a long cycle life, grid batteries’ frequent replacements would not be worth the cost or manpower to install them. Next, li-ion batteries must be safe. New energy solutions need to be safer than their predecessors to satisfy governments and consumers. After safety, cost is a top consideration. Again, energy producers are seeking better solutions, and are unlikely to invest in equipment that costs much more than their current fossil fuel systems.

Power, runtime, and energy density are less important factors for green energy storage. These batteries do not need high power to release energy quickly – a steady flow is enough to keep households running. The batteries also do not need extremely long runtimes since they will generally run for a few days at most until solar or wind energy offers power again. Finally, the batteries do not need to be particularly compact and energy dense since they will be used in energy plants and not in consumers’ homes or portable devices. Energy producers could increase energy storage by combining multiple batteries and do not need a single, super dense battery.

When battery developers are optimizing their designs for specific applications (e.g., consumer electronics, EV’s, grid storage), they must be able to select battery materials with the best runtime, cycle life, power, and energy density, while also verifying safety under different conditions. The multivariable aspect of material development and selection means that battery development depends heavily on chemistry and material R&D. In fact, a recent study at the Massachusetts Institute of Technology (MIT) concluded that more than 50% of lithium-ion battery’s 97% cost decline since the technology’s inception is attributed to chemistry and material science R&D. Thus, material R&D is hugely critical to successful lithium-ion batteries and means that analytical characterization of the materials comprising the main battery components for thermal, rheological, and molecular properties can lead to better performing and safer batteries.

For example, one critical material characteristic that you may have noticed when you use your laptop or pick up your phone after charging is that lithium-ion batteries tend to heat up. This warning and cooling of operating batteries means that battery materials need to be characterized by thermal analysis for such parameters as material melting point and decomposition temperature so that the overall battery performs and operates safely. Additionally, battery manufacturing involves a mixture of solid particles, binder and solvent undergoing a range of deformations during storage, mixing, coating, and drying. Rheology, the study of flow and deformation of materials, enables researchers to understand battery slurry formation, storage, and particle settling during those stages of the manufacturing process.

If you’d like to explore how thermal analysis and rheology can help support your battery material research, please visit TA Instruments’ battery material characterization website to learn more.