In recent years, the global demand for batteries has significantly increased. This demand is driven by incorporating energy storage in the power sector, expanding solar and wind power use, and rising interest in electric vehicles globally. Governmental investments and new regulations worldwide support this development and the rise of clean energy.
The lithium-ion battery (LIB) industry has grown significantly in the past five years, with a marked increase in the installed capacity of LIBs for energy storage applications. This expansion is attributed to lithium batteries’ superior energy density and cycle life, along with advancements in battery chemistry and manufacturing processes that have greatly reduced average battery costs.
With the global transition to greener energy accelerating, the need for increased battery capacity and efficient, safe, and sustainable battery technology has become more critical. However, battery development and manufacturing have a substantial environmental footprint today. The intensive sourcing/ mining, shipping, and disposal of the chemicals used in production contribute significantly to the negative climate impact.
Complex manufacturing processes and the chemical supply chains involved in battery development have an increased environmental impact. Because of governmental efforts worldwide to promote cleaner energy solutions, requirements tighten and call for “greener,” environmentally friendlier options for chemical raw materials and a more sustainable supply chain in battery development and production. In addition, the increasing demand for batteries has highlighted risks associated with the battery supply chain. These include supply chain dependencies and the need for battery recycling. There is a growing focus on diversifying battery chemistries and technology to mitigate these risks, optimize energy storage capacities, and improve overall sustainability.
Figure 2. Geographical distribution of the global battery supply chain. Source: IEA, Batteries and secure energy transitions
Alternative raw materials driving sustainability and availability in battery development
Metals like cobalt, nickel, copper, lithium, and rare earth minerals are commonly known as “critical materials,” meaning they are essential to current technology development and production processes. They also have a high risk of supply chain disruption due to their raw materials’ natural occurrence being highly geographically concentrated and thus prone to be affected by regulatory changes, trade restrictions, or political instability. Consequently, one of the most critical aspects of driving higher sustainability and supply chain resilience in battery R&D is the selection of raw materials to produce cathode and anode active materials.
Various alternative battery chemistries, including lithium-iron-phosphate (LFP) batteries, sodium-ion batteries (SIBs), and solid-state batteries (SSBs), are being researched as more sustainable and cost-effective storage solutions that improve supply chain constraints.
Lithium-iron-phosphate cathodes are already widely used in LIBs. One of the significant advantages of LFP batteries is their sustainable and stable chemical footprint, as they do not contain nickel or cobalt. This makes LFP batteries more environmentally friendly than nickel and cadmium-rich cathode chemistries. LFP batteries are less flammable and have a longer cycle life, enhancing their safety and durability. From an environmental and sustainability standpoint, LFP batteries benefit from the high availability of iron and phosphate resources, making them a more accessible, cost-effective option compared to other nickel-or cobalt-based cathode materials.
Sodium has been researched since the mid-20th century as a cathode material substitute for lithium. SIBs offer several advantages, making them a promising alternative for cost-effective energy storage with a lower environmental impact. Fewer critical minerals are required for SIB production compared to the dominant LIB. This reduces the dependence on scarce minerals and contributes to the overall economic viability. SIBs can use aluminum anode collectors instead of copper, which LIBs require. This substitution reduces the usage of copper, which is beneficial for sustainability efforts and helps minimize critical resource consumption. While the energy density and overall lifetime of SIBs are lower than those of LIBs today, future generations of SIBs are expected to reach parity. Overall, the combination of lower battery material costs, reduced dependence on critical minerals, and the potential to reduce copper usage positions SIBs as an attractive alternative to lithium-based technologies.
A further battery technology in the early stages of research and development is SSBs. SSBs are based on solid electrolytes, which offer improvements over current liquid electrolyte LIBs, such as higher energy density and safety. SSBs use different materials for their components, with lithium metal and silicon being among the most researched anode active materials. Three groups of solid electrolyte materials — oxide, sulfide, and polymer — are considered the most promising in optimizing SSB performance. Since SSBs do not contain flammable liquids, they are considered highly safe, even at the cell level. Depending on the materials used, SSBs may also offer increased sustainability benefits. However, the primary reason for selecting solid-state batteries in many applications is their superior energy density.
Next-generation battery technologies: greener innovation
LFP, SIB, and SSB comprise the next generation of battery technology. These battery chemistries represent promising alternatives to LIB, improving sustainability and mitigating the supply chain risk of battery development. Research into and commercialization of these new battery chemistries is rapidly advancing, and we can expect to see even more green technologies come to market.
Other battery types in the “next generation” category include zinc-ion and zinc-air batteries, aluminum- or magnesium-ion batteries, and sodium- and lithium-sulfur batteries. The latter are intensively researched because sulfur is a lightweight, relatively cheap, and abundant material, making it a good choice for lower-cost cathodes. Most of these chemistries are still in the early stages of research. Still, if developmental challenges like cycle stability can be overcome, they may offer promising low-cost battery options with a reduced environmental impact.
While the battery types discussed earlier in this article use the conventional battery setup and focus on substituting cathode and anode materials, there are also options being researched that evaluate alternative functionalities, such as redox Flow Batteries (RFBs). RFBs function differently than conventional batteries, as the energy is stored in the electrolyte of the battery instead of the electrode material. They offer affordability, reliability, and safety in stationary applications, positioning them as a potential major player in renewable energy storage. Most commercial RFBs use vanadium-based electrolytes and feature external tanks for storing electrolytes. During discharge, the electrolytes are pumped across electrodes separated by a membrane, releasing electrical energy. RFBs have scalability advantages, as increasing the volume of electrolyte tanks increases energy storage capacity without modifying the cell’s electrochemical components. At the same time, the risk of short-circuiting and thermal runaway is low due to electrolyte separation and the use of fireproof materials. RFBs are well-suited for applications requiring long discharge times, such as grid-scale energy storage.
Many of these next-generation battery technologies and chemistries will require continued research to reach the technical capabilities and popularity of current LIBs. Nevertheless, these R&D trends indicate a promising direction toward prioritized sustainability, supply chain stability, and safety in clean energy.
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