In:
Small, Wiley, Vol. 16, No. 26 ( 2020-07)
Abstract:
SnO 2 has been considered as a promising anode material for lithium‐ion batteries (LIBs) and sodium ion batteries (SIBs), but challenging as well for the low‐reversible conversion reaction and coulombic efficiency. To address these issues, herein, SnO 2 quantum dots (≈5 nm) embedded in porous N‐doped carbon matrix (SnO 2 /NC) are developed via a hydrothermal step combined with a self‐polymerization process at room temperature. The ultrasmall size in quantum dots can greatly shorten the ion diffusion distance and lower the internal strain, improving the conversion reaction efficiency and coulombic efficiency. The rich mesopores/micropores and highly conductive N‐doped carbon matrix can further enhance the overall conductivity and buffer effect of the composite. As a result, the optimized SnO 2 /NC‐2 composite for LIBs exhibits a high coulombic efficiency of 72.9%, a high discharge capacity of 1255.2 mAh g −1 at 0.1 A g −1 after 100 cycles and a long life‐span with a capacity of 753 mAh g −1 after 1500 cycles at 1 A g −1 . The SnO 2 /NC‐2 composite also displays excellent performance for SIBs, delivering a superior discharge capacity of 212.6 mAh g −1 at 1 A g −1 after 3000 cycles. These excellent results can be of visible significance for the size effect of the uniform quantum dots.
Type of Medium:
Online Resource
ISSN:
1613-6810
,
1613-6829
DOI:
10.1002/smll.202000681
Language:
English
Publisher:
Wiley
Publication Date:
2020
detail.hit.zdb_id:
2168935-0
Permalink