Lithium iron phosphate, or LFP batteries, are one of the chemistries currently leading the battery race. These batteries make use of low cost and ubiquitous materials like iron and phosphorus in the cathode coupled with carbon-based anodes.
Every EV is composed of interconnected battery cells that are cylindrical, prismatic or pouch, that are then arranged into modules. In turn, the modules are assembled together to form a pack. Consequently, the pack is integrated with thermal and battery management systems, electric motors and other auxiliary systems that form the EV powertrain, which is controlled by the EV’s software.
Nowadays, manufacturers are moving away from the small modules to use cell to pack technology instead. As the name implies, instead of building modules, the battery cells are directly integrated into the battery pack, thus reducing the number of components, increasing energy per volume and weight, and decreasing the overall cost. By combining cell to pack technology with LFP batteries characteristics and standards, EVs can become even more efficient and cost-effective.
Why the Cell to Pack Design?
EV manufacturers need high-performance, cost-effective and safe batteries.
In searching for these characteristics, battery manufacturers have turned to a standard battery pack configuration made up of numerous battery modules. Each of these modules consists of groups of individual battery cells. These modules and cells are typically liquid or air-cooled, monitored and managed by battery management systems.
However, this modular design is not ideal and not always the most optimal. Indeed, the inactive areas of the module including the housing, side plates, terminal plates, battery management, internal connectors and cooling systems all add weight, take up space, and decrease the battery pack’s energy density.
LFP Characteristics
With a range of benefits, LFP batteries are rapidly gaining popularity in the manufacture of EV batteries. Indeed, with a lower cost compared to other battery chemistries, long-term stability, lifetime and safety, LFP batteries have almost everything that car manufacturers are looking for. Nonetheless, the question remains about whether or not they will be enough to match consumers’ requirements.
Consumer High Demands
For over 130 years, fossil-fuelled transport has dominated the market. As a result, consumers have become accustomed to the functionality that comes with it. Whether it’s the long driving range or the high power-energy balance, consumers have developed high demands when it comes to their vehicles. This is especially true for the concerns surrounding the more limited driving range of most fully electric EVs, which is also known as range anxiety.
LFP Integration
While some EV manufacturers are talking about LFP, Tesla has already started using this technology in their vehicles while VW is also due to follow suit. Indeed, when producing the Model 3 in China, the opportunity to delve into using LFP batteries in the EVs presented itself. Moreover, when Tesla decided to use prismatic cells, they went with a cell to pack approach, minimizing the impact on range. Indeed by opting for LFP, Tesla is able to ensure the supply of shortage-prone nickel and cobalt needed for high-performance applications and in the case of China, adhere to the more lenient tolerance for shorter range.
Using Addionics Technology to Improve LFP
Though LFP batteries have a longer lifetime, better stability and tend to be safer, the LFP material itself has low electronic conductivity and the LFP cathodes have low areal density (g/cm2): Addionics 3D Electrodes can improve both. By altering the battery architecture, Addionics is able to increase the amount of active material, reduce the amount of inactive material and enable a higher areal density leading to a higher energy. Additionally, by combining LFP with cell to pack technology with Addionics 3D Electrodes, this can further improve the overall performance of battery packs.
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