Ultrahigh rate capability of manganese based olivine cathodes enabled by interfacial electron transport enhancement. (15th December 2022)

• Record Type: Journal Article
• Authors: Hu, Qiao; Liao, Jiaying; Xiao, Xiang; Wang, Xiaodan; Liu, Jinli; Song, Youzhi; Ren, Dongsheng; Zhang, Hao; Wang, Li; Chen, Zonghai; He, Xiangming
• Is Part Of: Nano energy. Volume 104(2022)Part A
• Publication Date: 2022-12-15
• Subjects: Lithium manganese iron phosphate -- Lithium vanadium phosphate -- Interfacial transport -- Affinitive conductor -- Rate performance; Nanoscience -- Periodicals; Nanotechnology -- Periodicals; Nanostructured materials -- Periodicals; Power resources -- Technological innovations -- Periodicals; Nanoscience; Nanostructured materials; Nanotechnology; Power resources -- Technological innovations; Periodicals; 621.042
• DOI: 10.1016/j.nanoen.2022.107895
• Languages: English
• ISSNs: 2211-2855

Abstract

Abstract: Manganese-based Olivine is a promising cathode candidate with high energy and low cost for Li-ion batteries (LIBs). Its rate capability and cyclability challenges still remain even with nano-size and carbon coating. Herein, an ultrahigh rate performance is achieved by introducing an affinitive conductor to enhance the interfacial electron transport of LiMn0.7 Fe0.3 PO4 via Li3 V2 (PO4 )3 . It is found that the Li3 V2 (PO4 )3 facilitates sp 2 hybridization to form a highly conductive carbon coating during the carbonized process. The composite 0.9LiMn0.7 Fe0.3 PO4 ·0.1Li3 V2 (PO4 )3 can deliver a capacity of 90.9 mAh g −1 and power density of 11444 W kg −1 at 50 C-rate. Both in situ X-ray diffraction and conductive-atomic force microscopy are conducted to understand the synergetic effect between LiMn0.7 Fe0.3 PO4 and Li3 V2 (PO4 )3 . The results suggest that the interfacial electron transfer between LiMn0.7 Fe0.3 PO4 particles and the electron conducting medium, such as binder/carbon black composite, is greatly improved so that the highly Li + conductive nature of olivine materials can be fully unleashed. This work demonstrates the importance of efficient interfacial electron transfer to the active cathode particles, and opens up a new venue for the rational design of high-energy and high-power batteries. Graphical Abstract: ga1 Highlights: A process to optimize the surface environment of LiMn0.7 Fe0.3 PO4 by the affinitive additive (Li3 V2 (PO4 )3 ) is developed. The form of carbon changes partially from sp 3 to sp 2 type hybridization. The reaction uniformity of 0.9LiMn0.7 Fe0.3 PO4 ·0.1Li3 V2 (PO4 )3 (0.9LMFP·0.1LVP) is greatly improved. 0.9LMFP·0.1LVP delivers specific capacities of 90.9 mAh g −1 and a power density of 11444 W kg −1 at 50 C rate. This work confirms that engineering the compatibility between the active material and the conductive carbon is important.