Designing interstitial boron-doped tunnel-type vanadium dioxide cathode for enhancing zinc ion storage capability

Abstract

Chemical doping is a powerful method to intrinsically tailor the electrochemical properties of electrode materials. Here, an interstitial boron-doped tunnel-type VO2(B) is constructed via a facile hydrothermal method. Various analysis techniques demonstrate that boron resides in the interstitial site of VO2(B) and such interstitial doping can boost the zinc storage kinetics and structural stability of VO2(B) cathode during cycling. Interestingly, we found that the boron doping level has a saturation limit peculiarity as proved by the quantitative analysis. Notably, the 2 at.% boron-doped VO2(B) shows enhanced zinc ion storage performance with a high storage capacity of 281.7 mAh g−1 at 0.1 A g−1, excellent rate performance of 142.2 mAh g−1 at 20 A g−1, and long cycle stability up to 1000 cycles with the capacity retention of 133.3 mAh g−1 at 5 A g−1. Additionally, the successful preparation of the boron-doped tunnel-type α-MnO2 further indicates that the interstitial boron doping approach is a general strategy, which supplies a new chance to design other types of functional electrode materials for multivalence batteries.