In:
Sustainable Energy & Fuels, Royal Society of Chemistry (RSC), Vol. 5, No. 24 ( 2021), p. 6381-6391
Abstract:
Nanostructured metal selenides based on conversion reactions are promising anode materials for sodium-ion batteries (SIBs). However, the repeat structural degradation accompanied by the detrimental intermediate of sodium selenides (Na x Se) leads them to suffer from continuous capacity decaying and under-voltage failure. In this work, CoSe 2 is chosen as a representative by the introduction of a polar Ti 3 C 2 T x matrix to alleviate the performance deterioration caused by the crystal structure evolution. CoSe 2 nanorods are in situ grown on the Ti 3 C 2 T x (CoSe 2 /Ti 3 C 2 T x ) surface by a simple one-step hydrothermal reaction during the reduction environment. A tight chemical bonding is formed between CoSe 2 and Ti 3 C 2 T x by oxygen bridging, which maintains the stable charge and ion transport during cycling. Meanwhile, Ti 3 C 2 T x facilitates copper coming from the collector being diffused in the electrode, and is involved in the electrochemical reaction in an ether-based electrolyte, resulting in CoSe 2 being partially converted to Cu 2− x Se after long cycles. Synchronously, Ti 3 C 2 T x improves the mutual transformation of Na x Se ↔ Na 2 Se during the intercalation/de-intercalation of metal selenides. Therefore, via optimizing the content of Ti 3 C 2 T x , the CoSe 2 /Ti 3 C 2 T x -10 composite obtains excellent long cycle stability, delivering a specific capacity of 343 mA h g −1 at 0.3 A g −1 after 1200 cycles with a capacity retention of 98%. Even at 10.0 A g −1 , CoSe 2 /Ti 3 C 2 T x -10 exerts about 200 mA h g −1 initial capacity, and remains at 140 mA h g −1 after 1400 cycles. The strategy of introducing a polar matrix to improve the long cycling stability of the metal selenide provides a new opportunity for the development of new anode materials for SIBs.
Type of Medium:
Online Resource
ISSN:
2398-4902
Language:
English
Publisher:
Royal Society of Chemistry (RSC)
Publication Date:
2021
detail.hit.zdb_id:
2882651-6
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