What’s the future of energy storage?

In this article, let’s explore the promising alternatives to lithium-ion batteries that lie ahead. But before we delve into that, let’s briefly revisit how modern batteries operate and the multitude of challenges that confront this technology.

Before delving into the inner workings of competing technologies, let’s take a moment to revisit the fundamentals of rechargeable lithium-ion batteries and understand why they may not be the ideal choice in today’s world.

Every battery comprises a cathode (positive electrode), an anode (negative electrode), and an electrolyte medium. When you deplete a charged Li-ion battery, positively charged lithium ions migrate from the anode to the cathode. This movement also prompts a flow of electrons, capable of energizing electronic devices. Conversely, when you charge a Li-ion battery, the same process occurs in reverse.

This cyclical process allows for the repeated charging and discharging of a Li-ion battery for hundreds of cycles. However, it’s important to note that this technology, despite its advantages, is not without its flaws.

Why is Li-on so problematic?

Li-ion batteries possess several drawbacks that have impacted various industries, ranging from iPhone manufacturing to the feasibility of electric vehicles. These issues encompass a wide array of challenges, such as:

• Safety: Lithium, a metal known for its high reactivity and flammability, requires careful handling. Li-ion batteries should be stored under specific temperature conditions to avoid overcharging or short circuits. Failure to do so can lead to a potentially hazardous chain reaction called thermal runaway, resulting in fires or even explosions.
• Scarcity: Lithium, a crucial element in Li-on batteries, is unfortunately limited on our planet. Compounding this issue, the majority of Lithium reserves are situated far from manufacturing centers.
• Sustainability: The production of Li-ion batteries relies on environmentally destructive mining practices to extract metals like lithium, cobalt, and nickel. Unfortunately, a significant portion of these valuable resources is concentrated in developing nations such as the Democratic Republic of Congo, where ethical mining practices have yet to be established. As a result, the production of Li-ion batteries contributes extensively to greenhouse gas emissions.
• Durability: It’s common knowledge that smartphone batteries have a limited lifespan. Typically, manufacturers guarantee battery performance for approximately 800 to 1,000 charge cycles, equivalent to daily charging over a span of three years. The reason behind this lies in the degradation of Li-ion batteries over time. The accumulation of chemical and physical stresses progressively diminishes the availability of lithium ions, resulting in a decrease in their ability to retain a charge.

It should come as no surprise, given the aforementioned challenges, that virtually all major tech companies are actively pursuing alternative battery technologies. Although many of these endeavors are still in their early stages, a select few hold the potential to revolutionize the power source for next-generation electric vehicles and other consumer electronics within the next decade. Waste no time! Here’s a concise rundown of the top lithium-ion alternatives and their advancements over the existing battery technology.

Sodium-ion batteries

Let’s begin by exploring a battery technology that maintains the fundamental Li-on framework we are familiar with. Sodium-ion batteries, in essence, replace lithium ions as the primary charge carriers with sodium. This seemingly small alteration holds significant implications for battery production, considering sodium’s greater abundance in comparison to lithium. Remarkably, sodium can be extracted from common salt found in oceans worldwide, potentially reducing the costs associated with battery manufacturing.

Moreover, this transition eliminates concerns related to storing and transporting lithium, a potentially hazardous substance. Nonetheless, it’s worth noting that sodium-ion batteries do possess some drawbacks. Physically larger ions compared to lithium result in lower energy density, impacting the range of electric vehicles and the runtime of smartphones in practical scenarios. Nevertheless, given the other notable advantages of sodium-ion batteries, further research into this technology is well justified.

Lithium-ion batteries commonly employ cobalt as the anode material, but sourcing this element has posed challenges. However, lithium-sulfur (Li-S) batteries present a potential solution by using sulfur as the cathode material instead. Aside from replacing cobalt, Li-S batteries offer several advantages, including higher energy density and lower production costs.

Nonetheless, the primary obstacle with lithium-sulfur batteries lies in their rapid degradation rate. Despite witnessing the use of Li-S batteries in a solar-powered plane as far back as 2008, further research is required before this technology becomes viable for everyday electronic devices.

Solid-state batteries

Lithium-ion batteries employ a liquid electrolyte medium that facilitates ion movement between electrodes. Typically, an organic compound serves as the electrolyte that can ignite under excessive heat or charging. To mitigate these risks, researchers have developed an alternative: solid-state batteries. Solid-state batteries rely on a robust inorganic electrolyte that can endure harsh environments and extreme temperature fluctuations.

In addition to reducing the risk of ignition, solid-state batteries boast higher energy storage capacity compared to their lithium-ion counterparts. The enhanced conductivity of the solid electrolyte also leads to accelerated charging times, promising improved device capacity and faster charging speeds with this technology.

Electric vehicle manufacturers have expressed significant interest in solid-state batteries. For instance, Honda plans to demonstrate the technology as early as 2024, while Toyota pursues a more conservative approach and aims to introduce commercial solid-state batteries after 2027.

While not exactly similar to rechargeable Li-ion batteries, hydrogen fuel cells have emerged as a popular clean energy alternative. They work by combining stored hydrogen gas with oxygen from the air to generate electricity and water vapor. In other words, the byproduct of this reaction is entirely environmentally-friendly.

However, there are some downsides to hydrogen fuel cells. For instance, in the automotive industry, it is necessary to establish a network of hydrogen filling stations. Additionally, the initial cost of building hydrogen fuel cells is considerably high. As a result, even though cars like the Toyota Mirai exist, only a few regions worldwide possess the necessary infrastructure to support refueling of their hydrogen tanks.

Aqueous magnesium batteries

Researchers have recently proposed using magnesium ions as charge carriers in a continuous effort to make rechargeable batteries safer and more eco-friendly. This approach offers several advantages. First and foremost, magnesium is widely available and has a higher ionic charge compared to lithium. Consequently, it allows for a higher energy density in batteries of the same size. Additionally, these batteries utilize an aqueous electrolyte, specifically water, instead of a flammable organic liquid.

Despite these promising advancements, it is important to note that this technology is still in its early stages of research. Several limitations currently hinder its potential as a viable lithium-ion battery alternative. For instance, the existing cathode materials that are compatible with lithium cannot be used for magnesium. Moreover, employing an aqueous electrolyte imposes a limitation on the maximum voltage that the battery can achieve since water breaks down at higher voltages.

Graphene, a single layer of carbon atoms arranged in a hexagonal lattice or honeycomb-like structure, possesses remarkable characteristics. With its ultra-thin and two-dimensional nature, graphene exhibits excellent electrical conductivity, lightweight composition, and robust physical structure. In 2021, GAC, a Chinese carmaker, made a groundbreaking announcement regarding graphene battery technology by achieving an impressive 80% charge in just eight minutes.

Despite the considerable hype surrounding graphene as a potential alternative to lithium-ion batteries, the commercial viability of products remains uncertain. The primary hindrance to widespread adoption is the high cost associated with graphene, currently valued at over $60,000 per metric ton. Consequently, its usage is restricted to minute quantities. Take, for instance, Ford, utilizing trace amounts of graphene in engines and fuel systems to dampen noise and enhance heat resistance.