In Situ Tin Doping to Enhance the Cycling Performance of 4.9 V LNMO Cathode Materials

LiNi<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.5</inf>Mn<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1.5</inf>O<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</inf> (LNMO) cathode material has the advantages of high energy density (650 Wh/kg), high discharge voltage (4.7 V vs Li+/Li), low raw material cost, low pollution, and high lithium ion transmission efficiency. It is a potential high power, low cost cobalt-free lithium-ion battery cathode material. However, the capacity decline of LNMO during high voltage charge and discharge processes leads to short cycle life, which limits its wide application and commercialization. To address this issue, this article uses in-situ Sn doping to enhance the cycle stability of LNMO. By uniformly mixing acetate salts in stoichiometric ratio and using one-step spray drying method to prepare undoped and Sn-doped LNMO cathode materials, this study systematically investigates the structural changes, morphological characteristics, and electrochemical performance before and after doping. The capacity retention rates of Sn-doped LNMO materials after 350 cycles at 0.7C are 93.5% and 94.5%, respectively, significantly higher than the undoped 80.8%, indicating that in-situ Sn doping can significantly enhance cycle performance. This study demonstrates that the LiNi<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.5</inf>Mn<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1.46</inf>O<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.04</inf> electrode prepared by spray drying method, with its simple and straightforward synthesis process and excellent electrochemical performance, has the potential to become a high-performance lithium-ion batteries cathode material.