Capacity Enhancement of the Quenched Li-Ni-Mn-Co Oxide High-voltage Li-ion Battery Positive Electrode. (10th May 2017)

• Record Type: Journal Article
• Authors: Jena, Anirudha; Lee, Cho-Hsueh; Pang, Wei Kong; Peterson, Vanessa K.; Sharma, Neeraj; Wang, Chun-Chieh; Song, Yen-Fang; Lin, Chun-Che; Chang, Ho; Liu, Ru-Shi
• Is Part Of: Electrochimica acta. Volume 236(2017)
• Page Start: 10
• Page End: 17
• Publication Date: 2017-05-10
• Subjects: Li-rich high voltage cathode -- quenching -- neutron powder diffraction -- transmission X-ray microscopy; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2017.03.163
• Languages: English
• ISSNs: 0013-4686

Abstract

Graphical abstract: Highlights: Co-precipitation method has been used to obtain Li1.207 Ni0.127 Mn0.54 Co0.127 O2 . Slow cooled and air quenched samples are obtained and characterized. Unique spheres are obtained quenching than fragments in slow cooling. Quenched sample show higher specific capacity due to easier Li-ion passage in bulk. Abstract: Li-rich metal oxides, regarded as a high-voltage composite cathode, is currently one of the hottest positive electrode material for lithium-ion batteries, due to its high-capacity and high-energy performance. The crystallography, phase composition and morphology can be altered by synthesis parameters, which can influence drastically the capacity and cycling performance. In this work, we demonstrate Li1.207 Ni0.127 Mn0.54 Co0.127 O2, obtained by a co-precipitation method, exhibits super-high specific capacity up to 298 mAh g −1 and excellent capacity retention of ∼100% up to 50 cycles. Using neutron powder diffraction and transmission X-ray microscopy, we have found that the cooling-treatments applied after sintering during synthesis are crucially important in controlling the phase composition and morphology of the cathodes, thereby influencing the electrochemical performance. Unique spherical microstructure, larger lattice, and higher content of Li-rich monoclinic component can be achieved in the rapid quenching process, whereas severe particle cracking along with the smaller lattice and lower monoclinic component content is obtained when natural cooling of the furnace is applied. Combined with electrochemical impedance spectra, a plausible mechanism is described for the poorer specific capacity and cycling stability of the composite cathodes.