The Conversion Chemistry for High-Energy Cathodes of Rechargeable Sodium Batteries.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 31600049.
- Also identified by DOI 10.1021/acsnano.9b05635.
- No licence information is recorded for this record.
- Because redistribution is not established, this page shows the abstract only. Follow the links below for the full text.
Abstract
Herein, the Cu<sub>2</sub>P<sub>2</sub>O<sub>7</sub>/carbon-nanotube nanocomposite is reported as a cathode material based on a conversion reaction for rechargeable sodium batteries (RSBs). The nanocomposite electrode exhibits the large capacity of 355 mAh g<sup>-1</sup>, which is consistent with the 4 mol Na<sup>+</sup> storage per formula unit determined by first-principles calculation. Its average operation voltage is approximately 2.4 V (vs Na<sup>+</sup>/Na). Even at 1800 mA g<sup>-1</sup>, a capacity of 223 mAh g<sup>-1</sup> is maintained. Moreover, the composite electrode exhibits acceptable capacity retention of over 75% of the initial capacity for 300 cycles at 360 mA g<sup>-1</sup>. The overall conversion reaction mechanism on the Cu<sub>2</sub>P<sub>2</sub>O<sub>7</sub>/carbon-nanotube nanocomposite is determined to be Cu<sub>2</sub>P<sub>2</sub>O<sub>7</sub> + 4Na<sup>+</sup> + 4e<sup>-</sup> → 2Cu + Na<sub>4</sub>P<sub>2</sub>O<sub>7</sub> based on <i>operando/ex situ</i> structural and physicochemical analyses. The high energy density of the Cu<sub>2</sub>P<sub>2</sub>O<sub>7</sub>/carbon-nanotube nanocomposite (720 Wh kg<sup>-1</sup>) supported by this conversion chemistry indicates a high possibility of application of this material as a promising cathode candidate for RSBs.