Potassium Prussian blue-coated Li-rich cathode with enhanced lithium ion storage property. (September 2020)

• Record Type: Journal Article
• Authors: Xu, Zhou; Ci, Lijie; Yuan, Yifei; Nie, Xiangkun; Li, Jianwei; Cheng, Jun; Sun, Qing; Zhang, Yamin; Han, Guifang; Min, Guanghui; Lu, Jun
• Is Part Of: Nano energy. Volume 75(2020)
• Publication Date: 2020-09
• Subjects: Layered Li-Rich Mn-Based oxide (LRMO) -- Potassium prussian blue -- Surface modification -- Structural stability -- Electrochemical 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.2020.104942
• Languages: English
• ISSNs: 2211-2855

Abstract

Abstract: With high specific capacity, the layered Li-rich Mn-based oxide (LRMO) is a promising candidate cathode material for Li-ion batteries. However, the irreversible release of Li-ions during the first charging process, instability of LRMO/electrolyte interface and relatively low ion conductivity of LRMO result in low initial Coulombic efficiency (ICE), poor cycle stability and rate performance, which prohibit its further application. Interface engineering via additive coating is expected to effectively address these issues. Herein, we rely on potassium Prussian blue (KPB), a Li + acceptor with good ion conductivity, as a new coating material on LRMO particles. The KPB coating not only forms a protective layer on the surface of LRMO against electrolyte corrosion, but also functions as a host for Li + transport and accommodation, leading to enhanced ion conductivity and ICE of LRMO cathode. Consequently, 2 wt% KPB coated LRMO cathode achieved an initial discharge capacity of up to 281.7 mA h g −1 with an ICE of 85.69% compared to an ICE of 79.52% for the LRMO cathode without coating. The cycling and rate performance are also greatly improved as evidenced by the well maintained capacity of up to 176.8 mA h g −1 after 100 cycles at a current density of 0.5 C, compared to the limited capacity of only 135.3 mA h g −1 for the LRMO cathode without coating. This work pioneers the use of potassium Prussian blue as additive coating material to enhance performance of LRMO cathode, and we expect it to inspire the battery community with new strategies of material engineering/design toward practical application in high-energy lithium-ion batteries. Graphical abstract: Image 1 Highlights: Potassium Prussian blue is used as a coating material on the surface of LLO particles to improve Li + ion storage performance. As a Li-acceptor, Potassium Prussian blue layer preserves Li + upon discharge and improves initial Coulombic efficiency. Potassium Prussian blue layer protects LLO from electrolyte corrosion and maintains its structural stability during cycling.