Safety by Design: A Next-gen Blueprint for EV Batteries

October 1, 2025

Naoki Ota

A complete battery redesign results in a lighter, safer, more efficient, and more adaptable battery. (24M)

For more than three decades, the fundamental design of lithium-ion batteries has remained largely unchanged, tracing back to Sony’s original design in 1991 for small portable electronics. While impressive advancements have been made in materials, chemistry, and manufacturing efficiencies, the core design has remained the same. This legacy design, initially developed for small, low-voltage, low-energy-density applications, has now become a significant bottleneck for the automotive industry and the future of electric vehicles.

Imagine only updating the apps on your phone without ever updating the operating system. No matter how modern the apps become, the system cannot keep up with new demands. At some point, performance stalls and the system hits a wall. This is the situation the EV industry faces today. We’re pushing decades-old battery architecture well past its limits.

By just optimizing around the edges, we’re building on a flawed foundation. The conventional battery cell and pack architectures were never designed for today’s EV demands, and its limitations are clear: persistent material waste, complex thermal management, heightened safety risks, and rigid formatting that constrains manufacturability.

The trade-off trap

As EV adoption accelerates, these battery limitations translate directly into costly trade-offs for automakers. With pressure to deliver longer range, faster charging, and higher performance, engineers are forced to trade one performance metric for another. For instance, striving for higher energy density often comes at the expense of safety, while pushing for lower costs might compromise performance or quality control. This approach, despite yielding some significant improvements since Sony’s original products in the early 1990s, is now facing diminishing returns.

Internal comparison test of identical NMC/graphite cells with and without 24M Impervio demonstrates the separator’s significant safety advantages. (24M)

In the current EV landscape and given global competition, battery fire safety may be the most dangerous trade off. Range and fast charging requirements have pushed batteries to their performance limits; however, these gains often come at the expense of safety. With projections of 250 million EVs on the road by 2030, thermal incidents are expected to rise unless battery technologies become inherently safer. Markets have already seen a 33% surge in EV thermal incidents, underscoring an upward trend in both safety risks and related expenses.

In 2025, EV battery-related incidents made headlines. One incident of a cargo ship blaze that destroyed 800 EVs in the Pacific was linked directly to thermal runaway. Widespread battery-related EV and hybrid recalls highlight the scale of the problem. Each recall can cost automakers up to $1 billion per model line, creating massive financial exposure as EV markets scale globally. Combined, these incidents spread fear, hinder adoption, and reveal the steep financial cost of faulty batteries.

Battery experts now classify today’s EV batteries as a “Severity 10” risk, the highest level on the Design Failure Mode and Effects Analysis (DFMEA) automotive safety scale, where failure poses an immediate and severe risk of injury or fatality. This reflects an industry consensus that current lithium-ion designs are no longer sufficient, and that incremental process adjustments will not solve the problem. To genuinely break free from this cycle of fires, recalls, and eroding consumer trust, the industry must confront the root cause: the outdated architecture of the battery itself. What’s needed is not more patches, but a design that embeds safety into the cell from the start.

The case for a ground-up redesign

EV batteries need a redesign that enables safety, cost, and performance to advance simultaneously, rather than trading one off against another. This means embedding safety directly into the cell architecture and streamlining manufacturing processes to reduce costs. This approach unlocks innovation potential, allowing for entirely new materials, cell formats, and production methods that were previously impossible with conventional designs.

One strategy is to focus on safety and flexibility at both the electrode and pack level. One of the primary causes of internal short circuits is the growth of dendrites, which can form during overcharging or regular wear and tear. Dendrites can pierce internal components, triggering a short circuit that can lead to fire. At 24M, we’ve developed a functional battery separator that transforms what was once a passive thin polymer into an active safety component. Our 24M Impervio technology suppresses dendrite growth in the electrolyte and monitors the cell’s state-of-health. This enables it to detect internal shorts, even in overcharged batteries, before they escalate into thermal runaway. Built on conventional separator materials, 24M Impervio integrates directly into existing cells, delivering a new layer of safety from inside the battery itself.

But solving for safety alone isn’t enough. To fully unlock next-generation EV batteries, safety must be paired with better design flexibility. Electrodes that are integrated directly into the pack eliminate the need for traditional cells and modules and, at 24M, enable up to 50% more range and a more flexible design for a streamlined manufacturing process.

We need more innovations like these that move the industry beyond incremental tweaks and provide a fundamentally safer, more efficient, and more adaptable battery blueprint. By embedding safety and performance into the architecture itself, we can deliver safer EV batteries that restore consumer trust, lower costs, and accelerate mass adoption worldwide.

Stop optimizing the past, start building the future

The battery industry stands at an undeniable inflection point. Legacy designs can no longer keep up. They weren’t meant to power the current EV era and consumer demands. The path forward is not more patches, but a proven battery redesign rooted in safety and flexibility.

The next decade of EV growth will depend on solving the battery safety problem. Regulators, automakers, and consumers alike need confidence that EVs won’t trade performance gains for fire risk. At the same time, the industry must ensure resilient supply chains, scalable manufacturing, and affordable recycling solutions.

By abandoning outdated thinking and building a new foundation for energy storage, we can deliver safer, more scalable, and more flexible batteries than ever before. This new approach is necessary to enable a full transition to EVs with the implementation of new battery architectures.

Naoki Ota is president & CEO of 24M Technologies and wrote this article for SAE Media.