Ten Thousand-Cycle Ultrafast Energy Storage of Wadsley-Roth Phase Fe-Nb Oxides with a Desolvation Promoting Interfacial Layer.

Yang, Yang; Zhu, He; Yang, Fei; Yang, Fan; Chen, Dongjiang; Wen, Zhipeng; Wu, Dongzheng; Ye, Minghui et al. · Nano Lett · 2021

basic_science · Level V

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Abstract

Developing advanced electrode materials with enhanced charge-transfer kinetics is the key to realizing fast energy storage technologies. Commonly used modification strategies, such as nanoengineering and carbon coating, are mainly focused on electron transfer and bulk Li<sup>+</sup> diffusion. Nonetheless, the desolvation behavior, which is considered as the rate-limiting process for charge-storage, is rarely studied. Herein, we designed a nitridation layer on the surface of Wadsley-Roth phase FeNb<sub>11</sub>O<sub>29</sub> (FNO<sub>-<i>x</i></sub>@N) to act as a desolvation promoter. Theoretical calculations demonstrate that the adsorption and desolvation of solvated Li<sup>+</sup> is efficiently improved at FNO<sub>-<i>x</i></sub>@N/electrolyte interphase, leading to the reduced desolvation energy barrier. Moreover, the nitridation layer can also help to prevent solvent cointercalation during Li<sup>+</sup> insertion, leading to advantageous shrinkage of block area and reduced volume change of lattice cell during cycling. Consequently, FNO<sub>-<i>x</i></sub>@N exhibits a high-rate capacity of 129.7 mAh g<sup>-1</sup> with negligible capacity decay for 10 000 cycles.