Publikationsdatum:
2018
Beschreibung:
〈p〉Publication date: 15 February 2019〈/p〉
〈p〉〈b〉Source:〈/b〉 Journal of Power Sources, Volume 413〈/p〉
〈p〉Author(s): Ryohei Morita, Kazuma Gotoh, Mouad Dahbi, Kei Kubota, Shinichi Komaba, Kazuyasu Tokiwa, Saeid Arabnejad, Koichi Yamashita, Kenzo Deguchi, Shinobu Ohki, Tadashi Shimizu, Robert Laskowski, Hiroyuki Ishida〈/p〉
〈div xml:lang="en"〉
〈h5〉Abstract〈/h5〉
〈div〉〈p〉Phosphorus is a promising material for the electrode in sodium ion batteries (NIBs). In this study, the states of Na〈sub〉x〈/sub〉P〈sub〉y〈/sub〉 compounds synthesized by thermochemical reaction and electrochemical sodiation were compared using solid state 〈sup〉23〈/sup〉Na magic angle spinning (MAS) NMR, 〈sup〉23〈/sup〉Na multiple quantum (MQ) MAS NMR, and 〈sup〉31〈/sup〉P MAS NMR. The NMR signals in thermochemically synthesized Na〈sub〉x〈/sub〉P〈sub〉y〈/sub〉 compounds (Na〈sub〉3〈/sub〉P, NaP, Na〈sub〉3〈/sub〉P〈sub〉7〈/sub〉, Na〈sub〉3〈/sub〉P〈sub〉11〈/sub〉, NaP〈sub〉7〈/sub〉) are assigned in reference to theoretical chemical shifts, based on first-principles calculations. Furthermore, the NMR signals in electrochemically prepared Na〈sub〉x〈/sub〉P〈sub〉y〈/sub〉 compounds after two sodiation/desodiation cycles are ascribed to Na〈sub〉3〈/sub〉P compounds and three amorphous compositions. The amorphous compounds ascribed to Na〈sub〉1−α〈/sub〉P (0 〈 α 〈 1), Na〈sub〉2−β〈/sub〉P (0 〈 β 〈 1), and Na〈sub〉3−γ〈/sub〉P (0 〈 γ 〈 1) are formed below 0.58 V in the charge and discharge process. These Na〈sub〉3〈/sub〉P and the amorphous phases overlapped in the range from 0.20 V (sodiation process) to 0.58 V (desodiation process). 〈sup〉23〈/sup〉Na and 〈sup〉31〈/sup〉P NMR spectra reveal reversible sodiation and desodiation processes in the third cycle.〈/p〉〈/div〉
〈/div〉
Print ISSN:
0378-7753
Digitale ISSN:
1873-2755
Thema:
Elektrotechnik, Elektronik, Nachrichtentechnik
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