钾离子电池锰基层状氧化物正极的研究进展

韩文哲, 赖青松, 高宣雯, 骆文彬

Advances toward manganese-based layered oxide cathodes for potassium-ion batteries

Wenzhe HAN, Qingsong LAI, Xuanwen GAO, Wenbin LUO

图4 (a) P3型K0.5MnO2 在电流密度为2 mA/g时的充放电曲线；(b)～(d) #1、#7和#14的原位XRD图；(e) P3-K0.5MnO2 的XRD峰比较；(f) O3和P3结构的XRD模拟图谱比较[48]；(g) P3-K0.75MnO2 和P3-K0.75[Co0.5Mn0.5]O2 的晶体结构示意图；(h) P3-K x [Co0.5Mn0.5]O2(0.25≤ x ≤0.75)的结构变化；(i) P3-K x [Co0.5Mn0.5]O2 的XRD谱图；(j) 通过DFT计算和XRD数据得到的P3-K x [Co0.5Mn0.5]O2 的晶格参数的对比图[57]；(k) 花生状P3型K0.45Mn0.5Co0.5O2 微粒的合成示意图[59]；(l)、(m) P3型K0.45Mn0.5Co0.5O2 的SEM图像[59]；(n) P3型K0.45Mn0.5Co0.5O2 在300 mA/g电流密度下的长期循环性能[59]；(o) K0.5MnO2 的循环伏安图

Fig. 4 (a) Typical charge/discharge profiles of P3-type K0.5MnO2 at a current rate of 2 mA/g; (b)～(d) In situ XRD pattern taken for 2 h scanning rate per pattern; (e) XRD peak comparison of as-prepared (scan #1), scan #7, and scan #14 P3-K0.5MnO2 at 18°～20°; (f) comparison with simulated XRD patterns of the O3 and P3structures[48]; (g) P3-K0.75MnO2 and P3-K0.75[Co0.5Mn0.5]O2; (h) Predicted structural change in P3-K x [Co0.5Mn0.5]O2 (0.25≤ x ≤0.75); (i) operando XRD patterns of P3-K x [Co0.5Mn0.5]O2; (j) comparison of c-lattice parameters of P3-K x [Co0.5Mn0.5]O2 obtained by first-principles calculations and operando XRD data[57]; (k) Schematic illustration of the synthesis of peanut-like P3-type K0.45Mn0.5Co0.5O2 microparticles[59]; (l), (m) SEM images of P3-type K0.45Mn0.5Co0.5O2; (n) long-term cycling performance of K0.45Mn0.5Co0.5O2 at 300 mA/g; (o) Cyclic voltammograms at a scan rate of 0.03 mV/s