The dangers of a battery 'monoculture'

As 2024 gets underway, the direction of rechargeable battery design continues to have major implications for the mining industry. A range of renewable power technologies are under development and expansion across the globe to replace fossil fuels. These advancements and the continued electric vehicle push driving the need for increased energy storage capacity, continue to add to the world's energy transition minerals shopping list.

The numbers are already in – the new mines needed to build up stockpiles of minerals critical to the energy transition are going to take at least a decade. Policies and international partnerships take time, and leadership changes can throw a wrench in even the most promising long-term plans.

The best scenario for the mining supply to keep pace with demand is if multiple battery technologies that diversify the supply chain are adopted for EV and renewable energy storage.

While batteries don't make one immediately think of agricultural metaphors, the rapid evolution of a global energy transition has industries reinventing themselves at a rate that demands flexibility and ingenuity. A universally accepted battery design 'monoculture' would put unnecessary pressure on the industry to find massive feedstocks to keep production humming.

Relying on problematic and heavily imported materials leaves the U.S. energy and transportation industries on shaky ground, not to mention the promised climate policies for 2025. While these necessary mineral components are still at risk, there won't-and shouldn't-be a one-size-fits-all solution.

Diversifying demand

With affected industries avidly seeking the perfect energy storage design for their needs, 'building a better battery' should be an ongoing process, not a specialization.

Lithium-ion battery performance and cost are constantly improving, however, key material supplies such as lithium, nickel, and cobalt are still limited-access when compared to the roughly 1.4 billion EVs it would take to replace all of the internal combustion vehicles on global highways, compelling the development of alternative battery chemistries.

Researchers are prioritizing material and product designs that reduce the use of critical minerals. Although lithium batteries continue to be the standard for EVs, the unique priorities of stationary energy storage – where lifespan is typically more important than battery size – provide ongoing opportunities in chemistry and materials research and development.

The adoption rate of iron phosphate, solid-state, or sodium-ion batteries in EVs will influence the supply and demand dynamics of nickel, cobalt, and other metals in standard lithium-ion batteries. Grid-scale battery storage systems have their own growing impact on the future of battery technology as well.

"There is a lot of value in optimizing designs for battery applications beyond transportation," said Andrew Colclasure, an energy storage researcher at the National Renewable Energy Laboratory. "Our increased focus on stationary batteries is challenging researchers to get creative with materials development, including earth-abundant or readily available materials."

In engineering electrical, electrochemical, and thermal energy storage, the focus is on novel properties and improved materials capabilities. Advancements in optimization and stability are being sought at every level of battery architecture including electrodes, membranes, and electrolytes as well as the structures of cells, modules, packs, and complete energy systems.

Technologies to watch for

Driven by a short deadline for green solutions, few emerging technologies are as dynamic and fundamental as batteries today. While demand for EVs may wax and wane with economies, battery development will continue to accelerate in 2024.

• Li-ion batteries dominate the stationary battery storage market for now – but competition is coming in the form of liquid-metal, zinc-air, and redox flow batteries, to name a few.

• Two prominent lithium-ion cathode chemistries will continue to vie for dominance in 2024. The West has historically preferred nickel-manganese-cobalt (NMC) batteries, while China favors lithium-iron-phosphate (LFP) batteries, which are becoming more of an international contender for companies like Tesla, Ford, and Volkswagen.

• Promising alternatives include lithium-sulfur, a greater capacity and lightweight alternative without nickel, cobalt or manganese.

• Sodium batteries were first produced in the 1980s, with sodium replacing lithium. Sodium is cheap, widely available, and environmentally friendly. Manufacturers such as China's CATL and Sweden's Northvolt have shown interest in the technology for potential commercial use.

• Metal-air battery systems are also lighter and more efficient, producing electricity from the reaction of oxygen in the air with metals such as aluminum, iron, lithium, sodium, or zinc. In metal-air batteries, the anode material is most of the volume, leading to some of the highest energy densities in battery design.

• The family of liquid metal batteries has benefits, including ultrafast electrode charge-transfer kinetics and resistance to microstructural electrode degradation. Liquid metals operational at room temperatures circumvent issues of thermal management, corrosive reactions, and hermetic sealing.

• The quest for solid-state batteries is already seeing exciting new milestones. Replacing the common liquid electrolyte with a solid ceramic could unlock batteries with higher energy density, faster charging, and improved safety. Companies to watch include Solid Power (partnering with BMW and Ford), Albermarle, QuantumScape (funded in part by Volkswagon), Toyota, Hyundai ,and Nissan.

• The most common capacitors in use today have drawbacks; notably poor retention of stored energy, exacerbated at higher temperatures. Hybrid lithium-ion capacitors take advantage of both designs, providing long life expectancy and a higher density without the leakage, thermal runaway, or short-circuiting issues that plague rechargeable batteries. A key application for hybrid capacitor designs is energy harvesting devices, as they can take advantage of power conversion technologies with minimal energy bleed while storing and releasing energy on demand. Expect to see many manufacturers creating new applications utilizing this innovative technology in the coming year.

After EVs, stationary storage

Large-scale energy storage systems have three main categories – on-grid, off-grid and mobile.

On-grid stationary applications are the standard for storing large-scale power produced by solar panels and the like. They add buffer capacity and reinforce residential and commercial energy usage.

Off-grid stationary applications, or independent energy storage, provide stable power access to isolated systems that are not connected to the primary electrical grid, powering anything from remote cabins to cruise ships. Stationary applications which don't have EVs' size limitations can also explore other less energy-dense BSs technologies.

Mobile charging stations are similarly designed for simple and quick deployment to another location. Today, off-grid and mobile chargers can be implemented to protect against overburdening existing charging infrastructure.

As a promising and readily scalable second-life EV battery application, stationary and mobile energy storage solutions are influenced by continuing vehicle production as much as original equipment manufacturing.

Battery recycling remains a hot topic in 2024, driven by concerns over materials availability and waste reduction. Second-life batteries are a cheap and efficient emerging business opportunity ready-made to solve the intermittence of renewable energy sources like wind and solar.

For example, Volvo recycled 48 end-of-life EV batteries in a 2021 experimental partnership with Nordic energy producer Fortum and Swedish energy management solution provider Comsys. The collaboration produced a 250 kilowatt-hour energy storage system at Fortum's Swedish hydropower plant on the Ljusnan River.

"Volvo Cars has big ambitions with regards to the circular economy and we are putting great effort in finding new business models that enable us to maximize battery usage over the course of their entire life cycle. This project is in line with those objectives and will offer us new insight about the batteries' lifespan and how they can be used outside of our cars," said Susanne Hägglund, head of Volvo's car service business, in a Fortum press release.

Recycling batteries also provides a chance to recover valuable materials like lithium. However, battery recycling technologies themselves are still in development, with companies actively working to make the process safer and more efficient.

Despite slow infrastructure adaptation and few regulations or guidelines in place, battery recycling as a profitable industry is a growing interest internationally, with facilities appearing all over the top EV-producing countries. In 2024, expect to see much more interest in developing and standardizing the recycling process.