Today, most lithium-ion batteries use the chemical element cobalt as the cathode material (which determines the battery's energy storage capacity). Compared to other chemical elements, cobalt cathode batteries offer longer battery life and are easier to measure and manage. However, cobalt mining has long been controversial.
Cobalt: The Ethical Dilemma of Electric Vehicle Battery Technology
Approximately 70% of the world's cobalt is mined in the Democratic Republic of Congo (DRC), a country notorious for poverty, corruption, and human rights issues.<sup>1</sup> In particular, cobalt mining in the DRC is also associated with child labor, unsafe mining conditions, miner abuse, and other illegal activities. As the electrification ecosystem demands a balance between social and environmental sustainability, there is growing interest in lower-cobalt battery chemistry (NMC and NCA) and cobalt-free battery chemistry (such as lithium iron phosphate (LFP)). Many manufacturers welcome this trend. In fact, Tesla plans to produce high-energy batteries with lower or no cobalt content to accelerate the path to sustainable energy.<sup>2</sup>
Source: Markets Insider; Global Economic Indicators Data Network [3,4,5]
LFP batteries are not only production-proven but have also been used in the industry for over a decade, making them a fully supported and preferred technology by leading original equipment manufacturers (OEMs). However, cobalt-based chemistry offers 10-20% higher energy density, resulting in longer battery life on a single charge. But this high performance comes with higher risk—cobalt has a lower ignition point than LFP, increasing the risk of battery fire. Furthermore, LFP batteries are cheaper to produce and more efficient at handling safety hazards such as breakdown or thermal runaway. The high power characteristics of LFP also allow for faster charging.
Electric vehicle manufacturers aim to use current battery technology in high-priced, high-performance (premium) vehicles, and LFP batteries in lower-end vehicles. These lower-end vehicles do not use cobalt, reducing costs and thus increasing their selling price. While LFP batteries are cheaper and safer to use than cobalt batteries, their discharge curves are flatter, making it difficult to accurately measure battery capacity.
ADI's Battery Management System (BMS) solution helps to solve this problem.
Analog Devices (ADI) offers industry-leading technology for accurate battery state-of-charge (SOC) measurement. ADI's BMS solutions accurately and efficiently manage the SOC of LFP batteries, unlocking their potential cost and safety advantages for the industry and significantly reducing the burden on automakers. Furthermore, LFP batteries offer higher power density, longer lifespan, and lower operating costs over a wider temperature range, making them ideal for battery reuse applications such as energy storage.
Ultimately, LFP batteries will lower the price barrier to purchasing electric vehicles, encouraging consumers to buy them. Currently, battery costs account for 51% of the list price of an electric vehicle.7 Furthermore, reducing the heavy reliance on cobalt will drive the industry to build a more ethical supply chain, and the advantages of LFP batteries will ultimately help achieve a more environmentally friendly and sustainable battery ecosystem and improve the efficiency of battery reuse.
Note:
1. Dafydd Davies. "Changes in Cobalt Supply Restrictions," PV Magazine, March 10, 2020.
2. Bridie Schmidt. "Tesla has been using high-energy nickel 4680 batteries for months," The Driven, September 28, 2020.
Nickel price (January 11, 2021), source: https://markets.businessinsider.com/commodities/nickel-price.
4. Price of aluminum (January 11, 2021), Source: https://markets.businessinsider.com/commodities/aluminum-price.
Price of 5 manganese (January 11, 2021), Source: https://tradingeconomics.com/commodity/manganese.
6BU-205: Types of Lithium Ions (January 11, 2021), Source: https://batteryuniversity.com/learn/article/types_of_lithium_ion.
7. Gustavo Henrique Ruffo. "What percentage of the total cost of an electric vehicle is the battery?" InsideEVs, February 5, 2020.
