Mixed Electronic and Ionic Conductor-Coated Cathode Material for High-Voltage Lithium Ion Battery

Abstract

A lithium ionic conductor, Li1.3Al0.3Ti1.7(PO4)3 (LATP), is introduced as a coating material on the surface of Mg-doped LiCoO2 to improve electrochemical performances for high-voltage (4.5 V) lithium ion batteries. Structure, morphology, elemental distribution, and electrical properties of the materials are thoroughly characterized by SEM, TEM, EELS, EDS, and C-AFM. The coating layer is electrically conductive with the aid of Mg ions which are used as a dopant for the active materials; therefore, this mixed electronic ionic conductor strongly enhances the electrochemical performances of initial capacity, cycling property, and rate capability. The LATP coating layer also demonstrates very promising applicability for 4.4 V prismatic full cells with graphite anode, which correspond to the 4.5 V half-cells with lithium anode. The 2900 mA h full cells show 85% of capacity retention after 500 cycles and more than 60% after 700 cycles.

Unveiling Nickel Chemistry in Stabilizing High‐Voltage Cobalt‐Rich Cathodes for Lithium‐Ion Batteries

“…Now that the experimental advantage of slight Ni bulk doping is obvious, we seek to understand the underlying mechanism. [24,34,35] Third, some studies of bulk doping show suppressed phase transitions yet there were no improvements in high-voltage cyclability (i.e., the case showing B but not A). The latter was also observed in the present work, as illustrated in the differential capacity versus voltage (dQ/dV) plot of the first charge/discharge curve of in Figure 2a.…”

Synthesis of Mg and Mn Doped LiCoO2and Effects on High Voltage Cycling

“…15,[20][21][22][23]26,[28][29][30] Most studies attribute the improvements in LCO cycling performance to Mg either providing structural stability 15,21,26,27 or improving the conductivity of the material. 20,23,29,30 Recently, Shim et al reported a retention of 85% capacity after 500 cycles and 60% after 700 cycles in 2900 mAh prismatic full cells (LCO/graphite) cycling up to 4.4 V (4.48 V vs Li/Li + ) utilizing a combination of ionic conductor coating and Mg doping. …”

“…15,[20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36] 15,[20][21][22][23]26,[28][29][30] Most studies attribute the improvements in LCO cycling performance to Mg either providing structural stability 15,21,26,27 or improving the conductivity of the material. 20,23,29,30 Recently, Shim et al reported a retention of 85% capacity after 500 cycles and 60% after 700 cycles in 2900 mAh prismatic full cells (LCO/graphite) cycling up to 4.4 V (4.48 V vs Li/Li + ) utilizing a combination of ionic conductor coating and Mg doping. 30 While much progress has been made for cycling below 4.5 V (vs. Li/Li + ), there are no studies, as far as the authors are aware of, on the long term effect of Mg doping on the O3-O6-O1 phase transitions which occur around 4.55 V and 4.63 V (vs. Li/Li + ) respectively.…”

Strategies to Build High‐Rate Cathode Materials for Na‐Ion Batteries

“…To date, the materials used as coating layer mainly include carbon materials, [44,[50][51][52] metal oxides, [22] conducting polymer, [53] and so on. Liu et al prepared Al 2 O 3 coated P2-Na 2/3 Ni 1/3 Mn 2/3 O 2 by simple wet chemistry method, which reduces the direct contact between electrode and electrolyte and alleviates side reaction.…”