Alternative To Lithium-Ion? Researchers Advance Safer, Affordable Aluminium-Ion Batteries

Bengaluru: A team of researchers in Bengaluru has developed a new composite material that could make aluminium-ion batteries more stable, safer, longer-lasting, sustainable, and affordable for future large-scale energy storage applications.

Aluminium-ion batteries have long been seen as a promising alternative to lithium-ion batteries because aluminium is abundant, inexpensive, can store more charge per atom than lithium, and is safer to handle. However, their commercial potential has been limited by the rapid degradation of cathode materials during repeated charging and discharging.

To address this, a research team led by Kavita Pandey at the Centre for Nano and Soft Matter Sciences (CeNS), Bengaluru, collaborated with researchers from the Shiv Nadar Institution of Eminence in Delhi. The collaborating team provided the theoretical framework for the study.

The researchers used MXene — a family of ultra-thin, highly conductive two-dimensional materials made from transition metal carbides or nitrides — to improve the performance of aluminium-ion batteries.

The study found that the MXene-based composite enhanced both the storage capacity and long-term cycling stability of the batteries, resulting in better battery life. Researchers identified vanadium dissolution as a major cause of battery degradation, which the MXene composite helped suppress, thereby improving the durability and overall performance of the battery.

Cathode Degradation Remains the Biggest Challenge

In an exclusive interview with ETV Bharat, Pandey explained that the key scientific challenge in aluminium-ion batteries is cathode degradation. An aluminium-ion battery mainly consists of an anode, cathode, separator, and electrolyte. In most existing systems, the electrolyte is water-based, or aqueous, which causes the cathode material to gradually dissolve during repeated charge and discharge cycles, reducing battery life and stability.

Talking about the battery life and long-term reliability, Pandey said that during every charge and discharge cycle in an aluminium-ion battery, aluminium ions move back and forth between the anode and cathode. For the battery to function efficiently over long periods, both the cathode and anode materials must remain structurally stable throughout these cycles. However, in vanadium-based cathodes, part of the vanadium gradually dissolves and leaches into the electrolyte during repeated cycling. This weakens the structural integrity of the cathode material over time, leading to a steady decline in battery performance and lifespan. Eventually, the cathode structure breaks down completely, causing the battery to fail.

Aqueous aluminium-ion battery device in different form factors (Photo Credit: Kavita Pandey)

Preventing this dissolution of vanadium in the electrolyte, she stressed, is one of the most critical challenges in improving the long-term stability and durability of aqueous aluminium-ion batteries.

To address this, the team combined vanadium oxide — a widely used cathode material known for its high theoretical capacity but poor cycling stability — with MXene, a highly conductive ultra-thin two-dimensional material. MXene acts as a conductive scaffold, helping stabilise the cathode structure while enabling smoother movement of electrons and aluminium ions. This significantly improved the battery’s stability and durability by reducing structural cracking and limiting material dissolution during repeated charge-discharge cycles. Pandey said the team selected the system to harness vanadium oxide’s high energy-storage potential while using MXene to overcome its short life cycle and enhance long-term performance.

Tests showed that the new material reduced vanadium dissolution into the electrolyte by more than fourfold compared with conventional cathodes. The study found that vanadium dissolution dropped sharply to 5.4 ppm from 28.3 ppm in conventional vanadium oxide cathodes. The battery retained more than 73 per cent of its original capacity after 100 charge-discharge cycles and around 59 per cent after 500 cycles.

Aluminium-Ion vs Lithium-Ion Batteries

Responding to where aluminium-ion batteries stand today amid concerns around lithium-ion battery costs, raw material dependence and safety, Pandey explained that comparing lithium-ion and aluminium-ion batteries is “like comparing apples and oranges” because both have different chemistries and use cases.

She said aluminium-ion batteries are unlikely to replace those used in smartphones, laptops or EVs, but hold strong potential for grid-scale energy storage, where space constraints are less critical.

According to her, aluminium-ion batteries are safer, environmentally friendly, use water-based electrolytes and rely on abundant aluminium, reducing supply chain concerns, costs and recycling challenges. She added that while aluminium-ion batteries may not completely replace lithium-ion technology, they could play an important role in niche applications where safety, sustainability and affordability are priorities.

Commercialisation Challenges Still Remain

On the biggest scientific and engineering hurdles preventing aluminium-ion batteries from becoming commercially viable at scale. Pandey stressed that the technology currently faces challenges in achieving energy densities comparable to lithium-ion batteries. Aluminium-ion batteries are still an emerging chemistry, whereas lithium-ion technology has undergone decades of intensive research, development and industrial scaling.

Aqueous aluminium-ion battery device in the bending condition (Photo Credit: Kavita Pandey)

She noted that the decades of research, manufacturing optimisation, and commercial investment behind lithium-ion batteries give them a major advantage in performance and cost competitiveness. Meanwhile, aluminium-ion battery technology remains at the research stage despite promising results. Substantial improvements are still needed before it becomes commercially viable.

She added that while some groups in Europe have progressed to prototyping, large-scale manufacturing capabilities have not yet been established, which remains a key barrier to commercial adoption.

Focus on Lightweight and Flexible Battery Systems

During the conversation, Pandey explained that the team focused on two major aspects of aluminium-ion battery development. The first was improving cathode stability to enhance the battery’s cycle life by reducing material degradation during repeated charge and discharge cycles. The second was an engineering and design challenge, which entailed developing lightweight and flexible aluminium-ion battery systems.

The team is exploring ways to redesign the battery components for applications where reducing weight is critical. She cited drones as one such example, noting that batteries account for nearly 50–60 per cent of a drone’s weight. Reducing battery weight could significantly improve flight endurance and efficiency. She said the goal is not to completely replace lithium-ion batteries, but to complement them in niche applications where aluminium-ion batteries can offer advantages such as lower weight, flexibility, and safety.

Pandey added that the challenges in aluminium-ion battery research vary depending on the specific application being targeted, with teams across India and globally working on different aspects of the technology.

Potential Beyond Aluminium-Ion Batteries

When asked whether the same design principle could be applied to battery chemistries beyond aluminium-ion systems, Pandey highlighted it is definitely possible, including for lithium-ion and sodium-ion batteries. However, she noted that these chemistries come with additional handling and manufacturing challenges.

According to her, lithium-ion and sodium-ion battery fabrication typically requires controlled inert atmospheres, such as glove boxes, to prevent reactions with air and moisture. In contrast, aluminium-ion batteries are comparatively easier to handle and design in flexible formats because they can often be processed under normal laboratory conditions. Pandey said that while similar engineering and design approaches can be extended to other battery chemistries, developing flexible and lightweight devices is currently more straightforward with aqueous aluminium-ion battery systems.

Position in Global Aluminium-Ion Battery Research

Responding to where the work stands in the global landscape of aluminium-ion battery research, Pandey described the results represent a meaningful technological advancement, particularly in combining improved battery performance with flexible device design, though not necessarily a dramatic breakthrough on their own. She added that the team had already published related research on flexible aluminium-ion battery devices in the Journal of Energy Storage last year, and the current work further strengthens that direction through both material and engineering innovations.

Talking about where aluminium-ion batteries could find their first real-world applications and how the technology could support India’s clean-energy ambitions, Pandey said she is advancing the technology through her startup, Urjen Technologies, which focuses on aluminium-ion battery design and development. She said that the startup is initially targeting two key areas: drones and IoT applications, where lightweight, flexible, and safer battery systems could offer significant advantages. According to her, these sectors could serve as early testing grounds for aluminium-ion batteries before wider commercial deployment in large-scale energy storage applications.