Ultrasmall ZnO Nanocrystals Confined in Honeycombed N‐Doped Carbon for High‐Performance and Stable Lithium/Sodium Ion Batteries

Abstract

ZnO with high theoretical capacity, low cost, natural abundance, and environmentally friendliness is regarded as a promising anode material for lithium‐ion batteries (LIBs). Unfortunately, it suffers from low conductivity and huge volume expansion during charge/discharge, which finally leads to rapid capacity degradation and poor rate capability. To overcome these issues, the honeycombed ZnO@N‐doped carbon (HC‐ZnO@NC) composite with improved performances is prepared in this work. The composite could be easily prepared as an anode for LIBs and sodium‐ion batteries (SIBs) by cross‐linking and subsequent calcining at a target temperature. When used as an anode for LIBs, it could possess a reversible capacity of 687 mAh g−1 after 500 cycles at a rate of 0.5C. At a higher rate of 2C, 388 mAh g−1 is observed after 500 cycles. Additionally, HC‐ZnO@NC also obtains a capacity of 166 mAh g−1 after 200 cycles at 0.5C for SIBs. When the rate reaches 1C, it maintains a capacity of 126 mAh g−1 after 1000 cycles. The outstanding electrochemical metal ion storage properties might be ascribed to the synergistic effect of honeycombed carbon architecture and micro ZnO nanocrystals.

Combustion Activation Induced Solid‐State Synthesis for N, B Co‐Doped Carbon/Zinc Borate Anode with a Boosting of Sodium Storage Performance

“…When compared with previous reported zinc borate or ZnO based anodes, CBZG anode is still competitive and superior (Figure 4e ). [ 15 , 25 , 44 , 45 , 46 , 47 , 48 , 49 , 50 ] The cycling performance of CBZG anode in ether‐ or ester‐based electrolyte is also displayed in Figure 4f,g . In contrast to ester‐based electrolyte, ether‐based electrolyte has a higher capacity retention of 80.0% after 500 cycles at 2 A g −1 , a larger capacity retention of 84.3% and nearly 100% columbic efficiency, even after 12 000 cycles at 10 A g −1 .…”