Na-ion batteries have attracted recent interest and start now to be counted as viable alternatives vs. Li ion technologies for specific applications. Indeed, recent works on phosphate-based Na-containing positive electrodes such as Na3V2(PO4)3 [1] and Na3V2(PO4)2F3 [2] have demonstrated excellent performances and can be considered as a new step on the way of sodium-ion technology development. However, like for the Li-ion technology, safety issues related to the use of flammable liquid electrolytes remain, especially due to the high reactivity of sodium with moisture and oxygen. All-solid state batteries, which use non-flammable solid electrolytes instead of organic liquid ones, have been proposed as strong candidates for alternative energy storage devices [3-5].
Following a recent successful approach developed for Li-ion all-solid state batteries [6, 7], we were able to assemble a monolithic all-solid state Na-ion battery using NASICON-type electrodes and electrolyte in a single step using the spark plasma sintering technique. Na3V2(PO4)3 was used as both positive (V4+/V3+ couple) and negative (V3+/V2+) electrodes while Na3Zr2Si2PO12 was used as the solid electrolyte. Both compositions present order-disorder phase transitions and present decent ionic conductivities of 1.5 x10 3 S cm-1 and 1.9 x10-4 S cm-1 at 200°C for Na3Zr2Si2PO12 and Na3V2(PO4)3, respectively. Thanks to a new experimental set-up, we report for the first time on the electrochemical characteristics of an all solid state Na-ion battery at temperatures as high as 200°C [8]. The battery operates at 1.8 V with 85% of the theoretical capacity attained at C/10 with good capacity retention, for an overall energy density of 1.87 x10-3 W h cm-2 and a capacity of 1.04 mA h cm-2.
[1]K. Saravanan, C.W. Mason, A. Rudola, K.H. Wong, P. Balaya, Advanced Energy Materials, 3 (2013) 444-450.
[2]A. Ponrouch, R. Dedryvere, D. Monti, A.E. Demet, J.-M. Ateba Mba, L. Croguennec, C. Masquelier, P. Johansson, M.R. Palacin, Energy & Environmental Science, 6 (2013) 2361-2369.
[3]T. Ohtomo, A. Hayashi, M. Tatsumisago, Y. Tsuchida, S. Hama, K. Kawamoto, Journal of Power Sources, 233 (2013) 231-235.
[4]M. Nagao, Y. Imade, H. Narisawa, T. Kobayashi, R. Watanabe, T. Yokoi, T. Tatsumi, R. Kanno, Journal of Power Sources, 222 (2013) 237-242.
[5]S. Boulineau, J.-M. Tarascon, J.-B. Leriche, V. Viallet, Solid State Ionics, 242 (2013) 45-48.
[6]A. Aboulaich, R. Bouchet, G. Delaizir, V. Seznec, L. Tortet, M. Morcrette, P. Rozier, J.M. Tarascon, V. Viallet, M. Dollé, Advanced Energy Materials, 1 (2011) 179-183.
[7]G. Delaizir, V. Viallet, A. Aboulaich, R. Bouchet, L. Tortet, V. Seznec, M. Morcrette, J.-M. Tarascon, P. Rozier, M. Dollé, Advanced Functional Materials, 22 (2012) 2140-2147.
[8]F. Lalère, J.B. Leriche, M. Courty, S. Boulineau, V. Viallet, C. Masquelier, V. Seznec, Journal of Power Sources, 247 (2014) 975-980.