Ti ─O─C Bonding at 2D Heterointerfaces of 3D Composites for Fast Sodium Ion Storage at High Mass Loading Level

The studies show the fast Na+ storage capacity of 3D MXene-reduced holey graphene oxide composite electrode at high mass loading level, that is attributed to the forming of Ti ─O─C bonding at heterointerfaces inside the 3D composites. Compared with typical commercial or research electrode materials, the composite electrode delivers a much higher areal capacity at a given current density, almost the highest value reported before. Abstract3D composite electrodes have shown extraordinary promise as high mass loading electrode materials for sodium ion batteries (SIBs). However, they usually show poor rate performance due to the sluggish Na+ kinetics at the heterointerfaces of the composites. Here, a 3D MXene-reduced holey graphene oxide (MXene-RHGO) composite electrode with Ti ─O─C bonding at 2D heterointerfaces of MXene and RHGO is developed. Density functional theory (DFT) calculations reveal the built-in electric fields (BIEFs) are enhanced by the formation of bridged interfacial Ti─O─C bonding, that lead to not only faster diffusion of Na+ at the heterointerfaces but also faster adsorption and migration of Na+ on the MXene surfaces. As a result, the 3D composite electrodes show impressive properties for fast Na+ storage. Under high current density of 10  mA cm−2, the 3D MXene-RHGO composite electrodes with high mass loading of 10  mg cm−2 achieve a strikingly high and stable areal capacity of 3  mAh cm−2, which is same as commercial LIBs and greatly ex...

Source: Small - April 18, 2024 Category: Nanotechnology Authors: Diwen Yu, Kaixuan Guo, Fengxiao Hou, Yangang Zhang, Xiaolin Ye, Yaohui Zhang, Puguang Ji, Umedjon Khalilov, Gongkai Wang, Xin Zhang, Kai Wang, Yuexian Song, Xiaobin Zhong, Hongtao Sun, Jian Zhu, Junfei Liang, Hua Wang Tags: Research Article Source Type: research