NATRON develops Prussian blue-based NIBs. Chapter 7 provides a practical introduction to the use of Prussian blue and its analogues (PBA) as electrodes in NIBs. The relevant physical and electrochemical properties of PBA-based electrodes and their use in batteries are described, and their performance compared with the current commercial state-of-the-art. The open framework of PBAs allows them to get high-rate capability and a long cycle life. Capacities over 150 mAh/g at potentials above 3 V versus sodium are achieved, placing them among the highest energy density positive electrodes of NIBs. The first commercialization of products based on PBAs occurred in 2019.
FARADION has collaborated with commercial partners to produce large-scale quantities of optimized active materials, electrolytes and electrodes to be incorporated into prototype NIBs cells. The technology is based on non-aqueous electrolyte and layered nickelate positive electrode coupled to a hard carbon negative electrode. Due to the proximity of the electrodes with those used in LIBs, these NIB prototype cells can be fabricated on existing Li-ion manufacturing lines that should be cost effective. Note that 12 Ah prototype pouch NIB cells delivering a specific energy higher than 140 Wh/kg have been produced and higher specific energy are announced in the near future (Chapter 8).
The development of these very promising NIB technologies by emerging and proactive battery companies all over the world should accelerate the adoption of NIBs into many new markets and applications.
I.4. References
Bauer, A., Song, J., Vail, S., Pan, W., Barker, J., and Lu, Y. (2018). The scale‐up and commercialization of nonaqueous Na‐ion battery technologies. Adv. Energy Mater., 8, 1702869.
Braconnier, J.J., Delmas, C., Fouassier, C., and Hagenmuller, P. (1981). Comportement electrochimique des phases NaxCoO2. Materials Research Bulletin, 15(12), 1797–1804.
Dahbi, M., Yabuuchi, N., Kubota, K., Tokiwac, K., and Komaba, S. (2014). Negative electrodes for Na-ion batteries. Phys. Chem. Chem. Phys., 16, 15007–15028.
Delmas, C., Braconnier, J.-J., Fouassier, C., and Hagenmuller, P. (1981). Electrochemical intercalation of sodium in NaxCoO2 bronzes. Solid State Ionics, 3–4, 165.
Delmas, C. (2018). Sodium and sodium-ion batteries: 50 years of research. Adv. Energy Mater., 8(17), 1703137.
Eshetua, G.-G., Diemant T., Hekmatfar, M., Grugeon, S., Behma, R., Laruelle, J., Armand, S., and Passerini, M., (2019). The scale-up and commercialization of nonaqueous na-ion battery technologies. Nano Energy, 55, 327–340.
Kim, H., Jihyun Hong, J., Yoon, G., Kim, H., Park, K.-Y., Park, M.-S., Yoon W.-S., and Kang, K. (2015). Sodium intercalation chemistry in graphite. Science Energy Environ. Sci., 8, 2963–2969.
Kim, S.-W., Seo, D.-H., Ma, X., Ceder, G., and Kang K. (2012). Electrode materials for rechargeable sodium‐ion batteries: Potential alternatives to current lithium‐ion batteries. Adv. Energy Mater., 2, 710.
Pan, H., Hu, Y.S., and Chen, L. (2013). Room-temperature stationary sodium-ion batteries for large-scale electric energy storage. Energy Environ. Sci., 6, 2338.
Peled, E., (1979). The electrochemical behavior of alkali and alkaline earth metals in nonaqueous battery systems—The solid electrolyte interphase model. Journal of The Electrochemical Society, 126(12), 2047.
Ponrouch, A., Marchante, E., Courty, M., Tarascon, J.-M., and Palacin, M.R. (2012). In search of an optimized electrolyte for Na-ion batteries. Energy Environ. Sci., 5, 8572.
Stevens, D.A. and Dahn, J.R. (2001). The mechanisms of lithium and sodium insertion in carbon materials. J. Electrochem. Soc., 148, A803.
Vikström, H., Davidsson, S., and Höök, M. (2013). Lithium availability and future production outlooks, Appl. Energy 110, 252.
1
Layered NaMO2 for the Positive Electrode
Shinichi KOMABA and Kei KUBOTA
Department of Applied Chemistry,
Tokyo University of Science, Japan
1.1. Research history of layered transition metal oxides as electrode materials for Na-ion batteries until 2009
Studies on room temperature Na-ion batteries started in the 1970s and electrochemical properties of Na//NaxCoO2 and Na//TiS2 cells were reported in 1980 (Braconnier et al. 1980; Newman Klemann 1980) when properties of Li//LiCoO2 were also first reported (Mizushima et al. 1980). The Li-ion batteries commercialized by Sony in 1991 consisted of LiCoO2 as a positive electrode material and carbon as a negative one, and have attracted much attention as high-voltage rechargeable batteries to date. On the other hand, Na-ion batteries are essentially based on the same chemistry and technology as Li-ion batteries, except for the charge carriers as Li+ and Na+ ions. Na-containing (sodiated) and Na-free (desodiated) materials are used for positive and negative electrodes, respectively, which correspond to the discharge state of the battery. The working voltage of the Na//NaxCoO2 cell was, however, ca. 1 V lower than that of the Li//LiCoO2 cell, resulting in lower energy density (Goodenough et al. 1980). Allied Corp. in the United States and Showa Denko K. K. and Hitachi, Ltd. in Japan undertook collaborative work on Na-ion batteries and filed patents of Na-Pb alloy//γ-NaxCoO2 cells (Shacklette et al. 1985, 1988; Shishikura et al. 1989) exhibiting good cycle stability but commercialization of the Na-ion batteries has not been achieved so far. The Na-Pb alloy//γ-NaxCoO2 cells needed a pre-sodiation process for the Pb negative electrode. A primary drawback of Na-ion batteries was the fact that the pre-sodiation process was required for practical use of any negative electrode materials at that time. In the 2010s, there was a general consensus that non-graphitizable carbon, so-called hard carbon, is known to deliver large reversible capacities and good capacity retention without any pre-sodiation (Stevens and Dahn 2000; Komaba et al. 2011).
Thus, another issue of the practical use of Na-ion is the low working potential of the positive electrode materials. The voltage of NaCoO2, isostructural to α-NaFeO2, in a Na cell at the voltage plateau region close to the end of discharge is ca. 2.5 V and much lower than ca. 3.9 V for α-NaFeO2 type LiCoO2 in a Li cell as shown in Figure 1.1. The large difference cannot be explained only by the standard redox potential of Na metal, which is lower than that of Li metal by ca. 0.3 V (Marcus 1985; Komaba et al. 2015). The voltage difference is much smaller than that between NaxCoO2 and LiCoO2 at the end of discharge (ΔV = ca. 1.5 V) (Kubota et al. 2014). The large voltage difference is probably due to larger ionic size and lower Lewis acidity of Na+ in comparison to Li+ as discussed by Goodenough et al. (1980).
Figure