Impacts of Surface Energy on Lithium Ion Intercalation Properties of V2O5

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• 作者：Wenda Ma ; Changkun Zhang ; Chaofeng Liu ; Xihui Nan ; Haoyu Fu ; Guozhong Cao
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2016
• 出版时间：August 3, 2016
• 年：2016
• 卷：8
• 期：30
• 页码：19542-19549
• 全文大小：510K
• 年卷期：0
• ISSN：1944-8252

文摘

Oxygen vacancies have demonstrated to be one of the most effective ways to alter electrochemical performance of electrodes for lithium ion batteries, though there is little information how oxygen vacancies affect the electrochemical properties. Vanadium pentoxide (V₂O₅) cathode has been investigated to explore the relationship among oxygen vacancies, surface energy, and electrochemical properties. The hydrogen-treated V₂O₅ (H–V₂O₅) sample synthesized via thermal treatment under H₂ atmosphere possesses a high surface energy (63 mJ m^–2) as compared to that of pristine V₂O₅ (40 mJ m^–2) and delivers a high reversible capacity of 273.4 mAh g^–1 at a current density of 50 mA g^–1, retaining 189.0 mAh g^–1 when the current density increases to 2 A g^–1. It also displays a capacity retention of 92% after 100 cycles at 150 mA g^–1. The presence of surface oxygen vacancies increases surface energy and possibly serves as a nucleation center to facilitate phase transition during lithium ion intercalation and deintercalation processes.