In:
Journal of Materials Chemistry A, Royal Society of Chemistry (RSC), Vol. 10, No. 37 ( 2022), p. 20080-20089
Abstract:
Although conversion-type electrodes deliver larger theoretical capacities than intercalation-type electrodes, their application as practical cathodes for Li rechargeable batteries is hindered by their intrinsically sluggish kinetics and low operating voltage. In this study, we demonstrate that the conversion-type electrochemical behaviors of Cu(PO 3 ) 2 in a Li-cell system are highly enhanced by amorpholization and carbon-mixing. In particular, the presence of the (PO 3 ) − polyanion in the structure enables a much higher operation voltage of Cu(PO 3 ) 2 relative to that of other conversion-type metal-oxide electrodes, resulting from the inductive effect by phosphorus with high electronegativity. As a result, the amorphorized Cu(PO 3 ) 2 /C composite delivers not only a large reversible capacity of ∼240 mA h g −1 at 12 mA g −1 but also an average operation voltage of ∼2.8 V ( vs. Li + /Li). Even at a high current density of 1200 mA g −1 , up to ∼60% of the specific capacity at 12 mA g −1 is retained. Furthermore, the capacity retention after 300 cycles at 480 mA g −1 is ∼77% of the initial capacity. This outstanding power capability and cyclability of the amorphorized Cu(PO 3 ) 2 /C composite differ markedly from the poor electrochemical properties of the well-crystallized Cu(PO 3 ) 2 /C composites, indicating the enhanced kinetics of the conversion reaction in Cu(PO 3 ) 2 by amorpholization. In addition, the reversible conversion-reaction mechanism of Cu(PO 3 ) 2 in a Li-cell system is demonstrated through various experimental measurements.
Type of Medium:
Online Resource
ISSN:
2050-7488
,
2050-7496
Language:
English
Publisher:
Royal Society of Chemistry (RSC)
Publication Date:
2022
detail.hit.zdb_id:
2702232-8
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