Mechanochemically synthesized amorphous superionic systems for solid-state batteries

• Published in: Solid state ionics 2002-06, Vol.148 (3), p.431-436
• Main Authors: Dalvi, Anshuman, Shahi, K
• Format: Article
• Language: English
• Subjects: Amorphous superionic conductors; Applied sciences; Ball-milling; Direct energy conversion and energy accumulation; Electrical engineering. Electrical power engineering; Electrical power engineering; Electrochemical conversion: primary and secondary batteries, fuel cells; Exact sciences and technology; Mechanochemical synthesis; Silver ion conductors
• ISSN: 0167-2738; 1872-7689
• DOI: 10.1016/S0167-2738(02)00083-8

Solid-state electrochemical cells of the type Ag|a-SIC|I 2 are fabricated using mechanochemically synthesized amorphous superionic conductors (a-SICs), AgI–Ag 2O–M x O y (M x O y =B 2O 3, V 2O 5, CrO 3) as electrolytes. The typical value of the conductivity of these systems is in the range 10 −2 to 10 −3 Ω −1 cm −1 and the transport number of Ag + ions is near unity. The mechanochemically synthesized powders were directly used as electrolytes. Constant load characteristics for various loads confirm the thermodynamic stability and competency of these materials as electrolytes. The cells are discharged at low ( J∼65 μA/cm 2) and high ( J∼105 μA/cm 2) drain currents and nominal cell capacities and energy densities were obtained. Nominal cell capacities for all these cells for low current discharge rates were found within 6–7% of the theoretical capacity of Ag/I 2 cell. Whereas, for high discharge rates, ∼3–4% of the theoretical value. A current density of ∼500 μA/cm 2 can be drawn safely without any serious polarization.