Author(s)

Masao Ohashi

Tokuyama College of Technology, Gakuendai, Shunan City, Japan.

A layer structured titanate Cs₂Ti₅O₁₁·(1 + x)H₂O (x = 0.70) has been prepared in a solid state reaction using Cs₂CO₃ and anatase type TiO₂ at 900°C. Ion exchange reactions of Cs⁺ in the interlayer space were studied in aqueous solutions. The single phases of Li⁺, Na⁺ and H⁺ exchange products were obtained. The three kinds of resulting titanates were evaluated for use as the cathodes in rechargeable sodium batteries after dehydrations by heating at 200°C in a vacuum. The electrochemical measurements showed that they exhibited the reversible Na⁺ intercalation-deintercalation in a voltage range of 0.5 - 3.5 V or 0.7 - 4.0 V. The Li⁺ exchange product showed the best performance of the discharge-charge capacities in this study. The initial Na⁺ intercalation-deintercalation capacities of the Li₂Ti₅O₁₁ were 120 mAh/g and 100 mAh/g; the amounts of Na⁺ correspond to 1.9 and 1.6 of the formula unit, respectively. The titanates are nontoxic, inexpensive and environmentally benign.

Cathode Material, Sodium Ion Battery, Layer Structured Titanate, Environmentally Benign

Ohashi, M. (2018) Novel Cathode Materials for Sodium Ion Batteries Derived from Layer Structured Titanate Cs₂Ti₅O₁₁·(1 + x)H₂O. Materials Sciences and Applications, 9, 526-533. doi: 10.4236/msa.2018.96037.