Surface Modification of Li(Ni0.6Co0.2Mn0.2)O₂ Cathode Materials by Nano-Al₂O₃ to Improve Electrochemical Performance in Lithium-Ion Batteries.

Kwang Yoo,Yeon Kang,Chang-Sam Kim,Kyoung Im

doi:10.3390/ma10111273

Kwang Yoo, Yeon Kang + Show 2 more

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https://doi.org/10.3390/ma10111273

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Abstract

Al2O3-coated Li(Ni0.6Co0.2Mn0.2)O2 cathode materials were prepared by simple surface modification in water media through a sol-gel process with a dispersant. The crystallinity and surface morphology of the samples were characterized through X-ray diffraction analysis and scanning electron microscopy observation. The Li(Ni0.6Co0.2Mn0.2)O2 cathode material was of a polycrystalline hexagonal structure and agglomerated with particles of approximately 0.3 to 0.8 μm in diameter. The nanosized Al2O3 particles of low concentration (0.06–0.12 wt %) were uniformly coated on the surface of Li(Ni0.6Co0.2Mn0.2)O2. Measurement of electrochemical properties showed that Li(Ni0.6Co0.2Mn0.2)O2 coated with Al2O3 of 0.08 wt % had a high initial discharge capacity of 206.9 mAh/g at a rate of 0.05 C over 3.0–4.5 V and high capacity retention of 94.5% at 0.5 C after 30 cycles (cf. uncoated sample: 206.1 mAh/g and 90.8%, respectively). The rate capability of this material was also improved, i.e., it showed a high discharge capacity of 166.3 mAh/g after 5 cycles at a rate of 2 C, whereas the uncoated sample showed 155.8 mAh/g under the same experimental conditions.

Highlights

IntroductionCurrent lithium-ion battery technology offers the highest energy density among the rechargeable battery technologies, dominating the market for mobile electronic devices for the past several decades
Current lithium-ion battery technology offers the highest energy density among the rechargeable battery technologies, dominating the market for mobile electronic devices for the past several decades.alternative forms of transportation, such as electric and plug-in hybrid electric vehicles, require significant improvements in energy density, safety, durability, cost, etc
Since Sony commercialized the lithium-ion secondary battery (C/LiCoO2 cell) in 1991, various cathode materials, which account for approximately 30% of materials in the lithium-ion battery, have been studied by many investigators

Summary

Introduction

Current lithium-ion battery technology offers the highest energy density among the rechargeable battery technologies, dominating the market for mobile electronic devices for the past several decades. Alternative forms of transportation, such as electric and plug-in hybrid electric vehicles, require significant improvements in energy density, safety, durability, cost, etc. The key to the successful development of novel and advanced rechargeable batteries is the materials [1]. Since Sony commercialized the lithium-ion secondary battery (C/LiCoO2 cell) in 1991, various cathode (positive electrode) materials, which account for approximately 30% of materials in the lithium-ion battery, have been studied by many investigators. LiCoO2 has been the dominating cathode material for commercial lithium-ion batteries owing to its high capacity, stable cycling, and easy production [2].

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