US 9,812,733 B2
Solid electrolyte and secondary battery
Shigeo Takeuchi, Kanagawa (JP); Hajime Yuzurihara, Kanagawa (JP); and Ryoji Kanno, Tokyo (JP)
Assigned to RICOH COMPANY, LTD., Tokyo (JP); and TOKYO INSTITUTE OF TECHNOLOGY, Tokyo (JP)
Filed by Shigeo Takeuchi, Kanagawa (JP); Hajime Yuzurihara, Kanagawa (JP); and Ryoji Kanno, Tokyo (JP)
Filed on Feb. 3, 2015, as Appl. No. 14/612,372.
Claims priority of application No. 2014-038548 (JP), filed on Feb. 28, 2014; and application No. 2014-185818 (JP), filed on Sep. 12, 2014.
Prior Publication US 2015/0249263 A1, Sep. 3, 2015
Int. Cl. H01M 6/18 (2006.01); H01M 10/0562 (2010.01); H01M 10/39 (2006.01); H01B 1/10 (2006.01); H01M 10/054 (2010.01)
CPC H01M 10/0562 (2013.01) [H01B 1/10 (2013.01); H01M 10/3918 (2013.01); H01M 10/054 (2013.01); H01M 2300/002 (2013.01); H01M 2300/0068 (2013.01)] 9 Claims
 
1. A sodium-sulfur based solid electrolyte, comprising:
a Na element;
a Ge element;
a P element; and
a S element,
wherein the sodium-sulfur based solid electrolyte has a Na ion conductivity of 1.5×10−4 S/cm or higher at 25° C., and
an atomic percentage (at. %) of each of the Na element, the Ge element, the P element, and the S element is as follows when a total of the respective elements in the sodium-sulfur based solid electrolyte is 100 at. %,
Na: from 38.8 at. % to 48.4 at. %
Ge: from 0.5 at. % to 8.9 at. %
P: from 3.9 at. % to 7.9 at. %
S: from 43.6 at. % to 48.6 at. %.