http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Shaji, Nitheesha,Santhoshkumar, P.,Nanthagopal, Murugan,Senthil, Chenrayan,Lee, Chang Woo Elsevier 2019 APPLIED SURFACE SCIENCE - Vol.491 No.-
<P><B>Abstract</B></P> <P>The performance of existing lithium-ion batteries (LIBs) is greatly hindered by the low specific capacity of graphite-based anodes (372 mAh g<SUP>−1</SUP>). Therefore, development of suitable anode materials that exhibit higher and stable capacity is necessary to improve performance. Transition metal oxides have attracted tremendous attention as next-generation anode materials for LIBs due to their high theoretical capacity. Herein, we report the synthesis of a porous CaFe<SUB>2</SUB>O<SUB>4</SUB> by a facile and time efficient solution combustion synthesis technique for use in an anode for LIBs. The as-prepared material exhibited improved electrochemical performance with specific discharge capacities of 441 mAh g<SUP>−1</SUP>, 518 mAh g<SUP>−1</SUP>, and 516 mAh g<SUP>−1</SUP> for the initial three cycles. It achieved stability with a deliverable specific discharge capacity of 551 mAh g<SUP>−1</SUP> after 150 cycles at a current density of 200 mA g<SUP>−1</SUP>. The porous CaFe<SUB>2</SUB>O<SUB>4</SUB> exhibits improved cyclic performance and rate capability. These improvements are attributed to the porous nature of active material and, more importantly, the presence of CaO, which effectively alleviates the volume changes by acting as a buffer matrix.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Porous CaFe<SUB>2</SUB>O<SUB>4</SUB> has been synthesized by a facile solution combustion synthesis technique. </LI> <LI> Mixed-metal oxides possessing electrochemically active-inactive constituents are reported. </LI> <LI> The porous CaFe<SUB>2</SUB>O<SUB>4</SUB> as an anode for LIBs exhibited improved electrochemical performances. </LI> <LI> The porous structure and the buffer matrices of CaO are owed for their improved activity. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
Glass ceramic coating on LiNi0.8Co0.1Mn0.1O2 cathode for Li-ion batteries
강형섭,Palanisamy Santhoshkumar,박재우,심규상,MURUGAN NANTHAGOPAL,이창우 한국화학공학회 2020 Korean Journal of Chemical Engineering Vol.37 No.8
Alleviating the surface degradation of Ni-rich cathode materials is desirable to achieve better electrochemical performance. Herein, we report the surface coating of lithium diborate (Li2O-2B2O3) over the Ni-rich LiNi0.8Co0.1Mn0.1O2 (NCM811) cathode material and the systematic investigation of its electrochemical properties. The structural and morphological properties were characterized through X-ray diffraction (XRD), high resolution field-emission scanning electron microscopy (HR FE-SEM), and high resolution field-emission transmission electron microscopy (HR FE-TEM). As a cathode material for Li-ion batteries, the 1.0 wt% Li2O-2B2O3 coated NCM811 exhibits better electrochemical properties than the bare NCM811 as well as 0.5 and 2wt% coated electrodes at room and elevated temperatures (60 oC). The improved electrochemical performance of 1.0 wt% Li2O-2B2O3 coated NCM811 might be due to the optimal coating amount that promotes better ion and electron movement along with prevention of surface degradation.