When it comes to aspects of safety and cycle longevity, Lithium Iron Phosphate (LFP) batteries outperform Nickel Manganese Cobalt (NMC) and Nickel Cobalt Aluminum (NCA), even though they exhibit a lower energy density. While NMC and NCA possess a significantly higher energy density than LFP on paper, this advantage is primarily noticeable in laboratory conditions. At the pack level, LFP’s specific energy and energy density performance aligns with that of NMC.
Those utilizing lithium batteries should thoroughly scrutinize the performance data of battery packs to make well-informed choices. On an individual cell level, NMC cells perform better than LFP cells under laboratory and real-world conditions. However, the performance data for battery packs presents a contrasting narrative.
This article draws upon the insights from the recent research paper “A non-academic perspective on the future of lithium-based batteries,” published in Nature Communications in January 2023. This paper comprehensively compares the substantial disparities between theoretical predictions and practical performance across the most prevalent lithium technologies.
NMC Performance Decreases 5-fold from Lab to Real-Life Battery Pack
Figure 1 presents the decline in specific energy and energy density of LFP and NCA technologies, transitioning from theoretical potential (“Theory”) to practical deployment in an installed device (“Pack”). While a significant difference is observed in specific energy (Wh/kg) and energy density (Wh/L) at the cell level between the two technologies, they demonstrate comparable performance when assessed at the pack level.
The information presented in the table stems from Figure 1, which juxtaposes LFP and NCA battery chemistries. For this comparison, the specific energy and energy density of NCA and NMC are presumed to be equivalent. However, actual data sources indicate a potential 5 to 15% discrepancy between NMC and NCA. The performance gap between LFP and NMC (or NCA) is considerably larger.
Theoretical estimations propose that NMC chemistry possesses a specific energy and energy density at least double that of LFP chemistry. Nevertheless, at the cell level, NMC only surpasses LFP by a factor of 1.5 for these metrics, and the two chemistries show equivalent performance at the pack level.
In real-world application, NMC cells perform at 36% of the theoretical maximum, while the pack performance is less than 20% of the theoretical prediction. Conversely, LFP cells achieve 45–48% of the theoretical output, and pack performance reaches around 37% of the theoretical level.
Key Reasons for the Significant Differences in Real-Life and Theoretical Performance of Batteries
Research on battery chemistry largely focuses on the performance of individual cells, frequently neglecting the decrease in specific energy and energy density metrics when these cells are integrated into modules or packs. Theoretical research is predominantly conducted at levels TRL1-TRL4 on the Technology Readiness Level scale. Scholars in the academic field often lack a thorough understanding of end-user demands and the crucial engineering processes for scalability and commercial battery production. Batteries are frequently subjected to tests under environmental conditions that deviate from those of real-world operations. This is particularly true for high-power applications in challenging outdoor and industrial environments.
The popularity of LFP is another contributing factor. Over the past two decades, battery manufacturers have devoted considerable effort into the design of these battery packs. The Cell-to-Pack (CTP) technology represents one of the most significant advancements in the assembly of industrial battery packs.
Cell-to-Pack Technology
Cell-to-Pack (CTP) technology strives to streamline lithium-ion batteries’ design and manufacturing processes. This strategy involves crafting the battery pack as a single entity that incorporates multiple cells, effectively doing away with the need for interconnects, connectors and additional components typically needed in traditional cell-to-module battery packs. The CTP methodology provides more efficient utilization of conductive materials (like aluminum and copper), cables, and the available space within a battery case.
CTP technology allows batteries to be more precisely and flexibly designed for specific applications, compared to what is achievable with cell-to-module technology. This is to align with the pack requirements for voltage and capacity. The adoption of CTP technology decreases the size, weight, and expenses associated with batteries, particularly for large industrial batteries. These are extensively used in forklifts in the materials handling sector and in other operations that demand high power.
Demand Drivers for LFP Lithium Batteries
The superior longevity and enhanced safety of LFP technology are key features. Our article, “New Tests Prove: LFP Lithium Batteries Live Longer than NMC,” provides data from tests on commercially available cells. For instance, the flashpoint temperature (the temperature at which a particular chemical can potentially trigger thermal runaway) for LFP batteries is markedly higher than that of NMC batteries. Refer to Figure 3 for more detailed information about lithium batteries with NMC and LFP cathodes.
The components of LFP batteries are more cost-effective than those of NMC. Nickel and cobalt, used in NMC, are pricey and frequently linked to unethical mining activities.
Significant performance enhancements in batteries have been achieved through gradual engineering improvements at both the cell level (including advancements in electrolyte and membrane materials) and the pack level, thanks to the introduction of CTP technology.
Mass production of LFP dramatically dropped battery cell prices, decreasing 98% from $5000/kWh in 1991 to $101/kWh in 2021. However, in 2022, a surge in battery metal prices led to an increase in the price per kWh of lithium batteries for the first time in the past decade. This resulted in a continuous preference for the less costly and more dependable LFP batteries over NMC batteries.
Conclusions
Given their lower cost and higher reliability than NMC batteries, LFP batteries maintain their position as the most practical and cost-effective technology in the market for numerous applications, including Electric Vehicles (EVs) and off-road electric industrial vehicles.
The progression of LFP technology is continuously advancing at both the cell and pack levels, especially with the implementation of CTP technology. Moreover, the enhancement of the Battery Management System (BMS) allows for real-time optimization of each cell discharge. This results in incremental improvements in a battery’s daily performance and contributes to the extension of its lifecycle.