Over the last twenty years, the electric vehicle (EV) has progressed from being an interesting, niche market solution for curbing the road transport sector’s carbon emissions, to becoming the “best-selling car on the planet” in 2023.
However, accelerating the widespread adoption of all-electric vehicles will require faster charging lithium-ion (Li-ion) batteries with higher energy density, reduced weight, unswerving safety, and long life.
So, even though the energy density of Li-ion batteries has increased from 80 Wh/kg in 1991 to around 300 Wh/kg in 2023, the industry is determined to further improve energy densities with some targets over 400 Wh/kg in the medium term. The problem is that today’s lithium-ion batteries using ternary layered oxide cathodes – NMC or NCA - and graphite-based anodes, are nearing their upper limit.
Thus, faced with the challenges of reducing weight and costs while increasing energy density in the short term, many manufacturers are shifting their attention to the battery pack - instead of relying on higher energy density at a cell level - with what is referred to as the “cell-to-pack” battery.
Rethinking the future of EVs with cell-to-pack technology
CTP battery designs were driven by manufacturers looking for a way to reduce costs by reducing the complexity of pack assembly.
So, while traditionally, batteries were constructed with cells grouped into modules, connected with cells connected in parallel and series to form the battery pack, this modular design had some advantages like handling and testability, but also had drawbacks. Each module came with it’s housing, terminal plates, side plates, internal connectors, battery management, and cooling systems – these all add weight, take up precious volume, require manufacturing, storing, aseembly and thus add cost and lower pack energy density.
CTP architetures eliminate modules entirely, instead assembling the cells directly into the battery pack. This increases volume utilization by about 15 to 50 percent, depending on the battery cell format.
Moreover, the CTP design can eliminate up to 40 percent of the parts required in a typical battery pack, which also saves costs and weight and leads to an increase in gravimetric energy density.
Can CTP approach offer more than extended range?
What is more, even though, initially, CTP battery design allowed manufacturers to optimize for cost and manufacturability, some implementations try and achieve more, from maximizing volume use to having the pack participate in the vehicle’s structural strength.
I-BEAM XFCTM: StoreDot’s approach to CTP with innovative structural cooling can accelerate demand for extreme fast charging EVs
StoreDot, a leader in innovative extreme fast charging (XFC) Li-ion battery technology for EVs, is well known for its industry-leading EV batteries that can be charged to 80 percent in just 10 minutes. Using proprietary materials and processes, the XFC technology enables extreme fast charging without sacrificing battery life, energy density, or safety.
Continuing our drive for innovation and pushing the boundaries, StoreDot recently introduced its own approach to CTP, named I-BEAM XFCTM. As the name implies, its structure incorporating cooling channels resembles I-shaped beams. In this concept StoreDot’s 100-in-5 electrodes are assembled into the cells, which are then directly integrated into the pack.
When compared to other CTP designs, StoreDot’s concept is not base on the traditional cell designs, rather imagining from new, what a cell designed for full integration as part of a pack system will look like. The concept not only focusses on optimized packing efficiency, but also offers integrated cooling to enable simple implementation of extreme fast charging capability.
This is an important step in overcoming range anxiety for EV drivers. StoreDot’s new concept alleviates drivers’ concerns, but it also offers car manufacturers a solution for the complexity and costs associated with integrating extreme fast charging into various vehicle platforms.
To ensure optimal fast charging without compromising the battery lifespan or safety, researchers at StoreDot have lodged a patent (18/450,355) for an innovative structural thermal management system ideally suited to large format CTP designs.
StoreDot’s I-BEAM XFCTM lays out a novel method of structural cooling, embedded at the core of the cell, that provides enhanced thermal management by eliminating localized hot spots and ensuring a uniform temperature across the battery pack.
Conclusion
StoreDot's innovative I-BEAM XFCTM battery technology is set to play a pivotal role in speeding up the widespread adoption of electric vehicles by allowing OEMs to offer longer-range, safe, and affordable fast-charging EVs to meet the demands of a growing market.
Driven by a comprehensive understanding of the demands and challenges of e-mobility StoreDot's I-BEAM XFCTM CTP concept with structural cooling offers:
- Faster charging: StoreDot's CTP battery technology with structural cooling can safely charge an EV to 80 percent in just 10 minutes. Or, more relevant to the EV driver, allows the addition of 100 miles of range in 5 minutes – irrespective of the SoC of the battery. This unique capability can significantly reduce range anxiety for EV drivers, giving them the confidence to enjoy the all-electric experience.
- Improved thermal management: The structural cooling eliminates localized hotspots in the battery pack and cells, thereby enhancing safety during extreme fast charging and improving cycle life.
- Increased energy density: With up to 20 percent higher energy density than traditional modular batteries, CTP battery packs can store more energy in the same space, thereby enabling longer-range EVs.
- Reduced weight: CTP battery packs are lighter than traditional modular battery packs. With growing concerns about the impact of heavier (compared to ICEs) EVs on efficiency, road deterioration, and other road users ’ safety, weight reduction is becoming a key focal area.
- Lower cost: CTP battery packs are less complex to manufacture than traditional modular battery packs. This can make EVs more affordable for consumers.
These key features are set to revolutionize the electric vehicle market. StoreDot's fast-charging CTP battery with structural cooling marks a major milestone in battery technology that will not only advance the state of batteries, but also redefine standards for EV efficiency, safety, and sustainability in the automotive industry.
Learn more about StoreDot’s I-BEAM XFCTM in this white paper: I-BEAM XFCTM: Shifting from cell-level chemistry to a holistic pack design
