Comparison of Structural Changes in Fully Delithiated Li[sub x][Ni[sub 1∕3]Co[sub 1∕3]Mn[sub 1∕3]]O[sub 2] and Li[sub x][Ni[sub 0.33]Co[sub 0.33]Mn[sub 0.30]Mg[sub 0.04]]O[sub 1.96]F[sub 0.04] Cathodes (x=0) upon Thermal Annealing

Yoojung Kim, Junho Eom, Min Gyu Kim, Yang-Kook Sun, Chong Seung Yoon, Jaephil Cho
2007 Journal of the Electrochemical Society  
͔O 1.96 F 0.04 cathodes ͑x = 0͒ occurring after full delithiation and subsequent heat-treatment at 200, 300, and 400°C using X-ray diffraction ͑XRD͒, transmission electron microscopy, and X-ray absorption spectra ͑XAS͒. In both cathodes, XRD patterns at x = 0 showed a layered O3-type structure ͑CdCl 2 ͒, but subsequent thermal annealing led to a similar structure decomposition to a Co 3 O 4 -type spinel and possible new O3-Ni 1/3 Mn 1/3 O 2+␦ -type layered phases. However, the XAS spectra
more » ... y showed that the Li x ͓Ni 0.33 Co 0.33 Mn 0.3 Mg 0.04 ͔O 1.96 F 0.04 exhibited much improved structural stability, showing a suppression of the phase decomposition to spinel Co 3 O 4 , as evidenced by a decrease in the FT peak intensity of corner-shared CoO 6 octahedra at ϳ3.2 Å.
doi:10.1149/1.2724761 fatcat:xh6mwbaio5al5k36ycmdvt3jke