“Running after Lithium"
Sodium is the real sustainable & lower-cost alternative to Lithium, but for next decade
SODIUM (NA), THE SIXTH most common element on earth crust and also an alkali metal, is very similar to Lithium (Li), but three times as heavy. About 1000 times more abundant than Lithium and easier to extract, Sodium is one of the strongest options for replacing Lithium in future battery chemistries, when fully ready for use.
Research activity on Sodium-ion batteries (SiB or NiB) materials has increased significantly in the past decade looking for a reliable, safe, and cost-effective substitute for Li-ion batteries (LiB). In fact, most of the research carried out on LiB has been successfully transferred to NiB [1], as cell construction are almost identical with those of commercially widespread LiB. But with a big delay in fundamental research, NiB clearly might not have reached the same mature level of LiB [2].
There are some key differences in electrochemical behavior of both batteries. While in LiB the anode is typically made of graphite, cathode materials vary across sub-types nickel, cobalt, or manganese. Instead of using graphite anode (due to bigger ionic radius of Sodium ions [1]), NiB have a hard carbon anode, providing flexibility in the anode material design [3]. On the cathode side, it doesn’t have nickel, manganese, and cobalt or LPF (Lithium iron phosphate) chemistries, but layered transition-metal oxides, eliminating the need for critical minerals such as Lithium and graphite.
NiB can be manufactured at reduced costs due to the abundance of the inexpensive core raw materials required, such as iron, manganese, and Sodium [4]. In contrast to Lithium, Sodium production is very sustainable, making NiB an ideal candidate for large-scale ESS stationary application. For mobility, however, NiB packs will be better suited for low-performance applications [5].
Faradion Ltd. (Sheffield, UK), one of the lead firms to exploit the potential of NiB, claims that its Na-ion cells have energy densities similar to commercial LFP LiB (160 Wh/kg at cell-level), and life cycles of 4,000 to 80 % capacity retention [6]. Faradion was acquired by Indian company Reliance New Energy Ltd. in Dec. 2021 and will incorporate Faradion’s technology at its proposed fully integrated energy storage giga-factory in Jamnagar, Western India [7].
Na-ion cells are still in R&D stage and info on performance is often preliminary, to be confirmed in demo/pilot projects. Possibly replacing some of the LFP share in electric vehicles (EVs) and energy storage, NiB are expected to reach 20 GWh by 2030 [8], which represents a small fraction of the LiB demand for EVs, around 3,000 GWh for that year [9], meaning that LiB will be by far unbeatable throughout the 2020s.
Compared to LiB, NiB is (up to 50%) cheaper to produce and uses less hard-to-find materials. Different to LiB, NiB can be completely discharged without damage and easily shipped, but has lower densities, higher weight (although Lithium accounts for just 10% of the battery's weight), shorter life cycles (for current technology), and will take more than half-a-decade for the industry to reach full-scale commercial operation.
28, November, 2022
* Professor at School of Electrical, Mechanical and Computer Engineering (EMC) of Federal University of Goiás (UFG)
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