In our work, a series of Li_1-xM_xCoO₂ (M = Na, x = 0–0.05) samples are synthesized by the solid-state calcination route. Electrochemical measurements show that high-rate capacities and high-voltage performances receive obvious improvements with an appropriate content of Na-doping. Specially, the capacity retention of Li_0.97Na_0.03CoO₂ and LiCoO₂ are 65.6% and 62.7% after the 100^th cycles at 3.0–4.5 V, respectively. The discharge capacity of Li_0.97Na_0.03CoO₂ compared with the pristine electrode LiCoO₂ is greatly enhanced from 125 to 135 mAh·g⁻¹ at the rate of 5C and 98 to 120 mAh·g⁻¹ at the rate of 10C (1C = 140 mA g⁻¹) respectively. With the larger radius of Na⁺ substituted for the smaller radius of Li⁺, it is found that the bond length of Li

在我们的工作中，通过固态煅烧路线合成了一系列Li _1-x M _x CoO ₂（M = Na，x = 0-0.05）样品。电化学测量表明，适当的Na掺杂含量可使高倍率容量和高电压性能得到明显改善。特别地，在3.0-4.5 V下进行第100^次循环后，Li _0.97 Na _0.03 CoO ₂和LiCoO ₂的容量保持率分别为65.6％和62.7％。与原始电极LiCoO ₂相比，Li _0.97 Na _0.03 CoO ₂的放电容量以5C的速率从125至135mAh·g ^-1大大增强，以10C的速率从98至120mAh·g ^-1（1C ＝ 140mA g ^-1）大大增强。发现用较大的Na ⁺半径代替较小的Li ⁺半径，发现Li的键长。