The Growing Focus on Battery Energy Density
by Jane Marsh
Batteries are going to power more than phones and portable game consoles. One day, they will keep houses lit and cars powered on cross-country treks.
The electrification of vehicles and the smart home revolution are making power storage more of an immediate need, especially as the grid adapts to renewables.
However, batteries need to hold more energy to keep electronics at 100%. That’s the main goal in the sustainable energy game — increasing battery energy density.
Decreasing Costs Prove Progress
Lithium-ion batteries and other variants have only sometimes been commercially viable or cost-effective. With the help of legislation and environmentalist efforts, electric cars are on roads and homes are on microgrids.
Battery costs for eco-conscious applications are down an astounding 90% since 2008 and will keep falling as adoption persists. It has allowed more experts to work on battery capacities in real-time applications.
Researchers must experiment with volumetric energy density — measured in Wh/L — and gravimetric energy density — measured in Wh/kg. Volume and mass must receive equal consideration for envisioning the denser battery of the future.
Additionally, power and energy density are separate concepts — experts generally measure energy density in watt-hours, whereas power is measured in watt output.
These all impact the charge rate of the battery. As batteries hold more power, professionals must ensure it doesn’t take too much longer to charge. Otherwise, it will be an unsustainable commercial option in cars, laptops, solar arrays, and earbuds.
People need more flexibility with energy usage apart from when systems immediately generate power. The market proves manufacturing and production are more cost-effective, so now it’s time to take the next step into making higher-density options meet the same economic standard.
It’s been done before, and companies are researching and developing innovative designs to hold more charge for extended periods.
Testing Battery Energy Storage Systems (BESSs)
BESSs are the key to solving energy loss and inconsistency concerns with renewables. Companies can place them on wind farms and corporate land, and private homes can have smaller BESSs for their household.
One of the critical factors in its efficiency and ability to hold more power is heat control. Overheating reduces efficacy over time, therefore reducing how much it can store. Cooling mechanisms — such as liquid-cooling chillers — are one way to assure long-term density even in unstable climates.
It also helps with rapid charging, which could present safety concerns if chargers attempt to refill high energy-density batteries in too short of a timeframe.
Another focus is size. The BESSs must be compact but large enough to contain components like cells and cooling. Batteries are known for their weight, especially in EVs — their heft is already a question of practicality in production, maintenance, and recycling infrastructure.
Therefore, batteries can’t afford to get heavier as they grow to hold more power. Mounting batteries and peripherals is one way to save space while keeping units protected, reducing maintenance costs.
These considerations are particularly critical for utility-scale applications if large commercial buildings want to incorporate and monetize renewable energy while redistributing it to the grid. Lithium-ion isn’t the only option in trying to increase capacity.
Investments in solid-state batteries are taking the world by storm as gigafactories break ground in Europe and inspire researchers worldwide.
Finding Better Materials
Lithium-ion is getting better at packing more energy in a smaller space, but raw material access will become a problem to the point where its progress won’t matter. Batteries rely too much on lithium and cobalt.
However, solid-state and flow batteries remove liquid electrolytes from the equation in pursuit of iron, chromium, or sodium for competitive energy density. For example, new cathode materials can extend the battery’s lifetime, as more resilient materials with larger capacities receive less pressure from high-intensity energy production.
Despite markets driving prices down, the scarcer these resources become, the more likely prices will fluctuate. Some companies still make lithium-based batteries, but they remove precious metals like nickel and cobalt for a more accessible, self-installable version.
Cobalt-free alternatives and sodium-aluminum versions are trying to enter the market with scale, but most experiments are still in development. These variants must solve the materials concern while promising better energy storage. Otherwise, they will fall out of fashion quickly.
Keeping the Lights On With Storage Systems
Households want to keep refrigerators cold during power outages and industrial fleets must reduce environmental impacts by going electric. High-density batteries are the solution to all these sustainable tech woes, so long as the storage proves practical.
Power consumption will only increase as the years go on, nations get more developed and tech becomes more accessible. Renewable energy has a lot to provide these systems if they have somewhere to store the leftovers. Innovations in high-density batteries give hope to expediting the clean energy future where all this is possible.
Article by Jane Marsh
Jane works as an environmental and energy writer. She is also the founder and editor-in-chief of