Abstract
In this work, the properties of silver-modified LiMn2O4 cathode materials are revisited. We study the influence of calcination atmosphere on the properties of the Ag-coated LiMn2O4 (Ag/LMO) and highlight the silver oxidation. The effect of the heat treatment in vacuum is compared with that in air by the characterization of the structure, specific surface area, Li transport properties and electrochemical performance of Ag/LMO composites. Surface analyses (XPS and Raman spectroscopy) show that the nature of the coating (~3 wt.%) differs with the calcination atmosphere: Ag/LMO(v) calcined in vacuum displays Ag nanospheres and minor AgO content on its surface (specific surface area of 4.1 m2 g−1), while Ag/LMO(a) treated in air is mainly covered by the AgO insulating phase (specific surface area of 0.6 m2 g−1). Electrochemical experiments emphasize that ~3 wt.% Ag coating is effective to minimize the drawbacks of the spinel LiMn2O4 (Mn dissolution, cycling instability, etc.). The Ag/LMO(v) electrode shows high capacity retention, good cyclability at C/2 rate and capacity fade of 0.06% per cycle (in 60 cycles).
Highlights
Today, lithium-ion batteries (LIBs) appear to be the dominant electrochemical generators to power many systems such as electronics devices, tools, hybrid and full electric vehicles (EVs), etc. as they are able to rapidly store and release large quantities of electricity
The present study shows that the porous architecture of Ag-coated LiMn2O4 (Ag/LiMn2 O4 (LMO)) composites has several advantages: (i) It can help to alleviate the structure changes caused by the lithium insertion/extraction, which significantly improves the cyclability of the cathode materials. (ii) The porous three-dimensional nanoparticles provide more active surface area for electrochemical reactions. (iii) The optimal pore diameter is better for energy storage as it favors the ion transport
LiMn2 O4 spinel cathode material has been coated with silver using a facile, scalable and wet-chemical method
Summary
Lithium-ion batteries (LIBs) appear to be the dominant electrochemical generators to power many systems such as electronics devices, tools, hybrid and full electric vehicles (EVs), etc. as they are able to rapidly store and release large quantities of electricity. Lithium-ion batteries (LIBs) appear to be the dominant electrochemical generators to power many systems such as electronics devices, tools, hybrid and full electric vehicles (EVs), etc. Huge research efforts impel improving LIB technology, especially the performance of positive electrodes (cathodes), which are the limiting electrochemical components in terms of energy density and rate capability [1,2,3]. Energies 2020, 13, 5194 as cathode materials. It has poor cycle stability (presence of Mn3+ Jahn–Teller (JT) ions) and insufficient rate capability due its low electrical conductivity that should be improved for use in EVs’ batteries [4,5,6]. Among the various techniques to prepare LMO materials, the solid-state reaction and coprecipitation methods are the most popular synthesis routes. The co-precipitation method is a wellknown wet-chemical technique for the growth of regular LMO particles with a narrow size distribution, compositional homogeneity and impurity free [7,8,9,10,11], while some impurities (i.e., Mn3 O4 and Mn2 O3 )
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
