Park Joon-Ki, Park Geun-Gyung, Kwak Hunho H, Hong Seung-Tae, Lee Jae-Won
Department of Energy Engineering, Dankook University, Cheonan 31116, Republic of Korea.
Department of Energy Science & Engineering, DGIST, Daegu 42988, Republic of Korea.
ACS Omega. 2018 Jan 11;3(1):361-368. doi: 10.1021/acsomega.7b01481. eCollection 2018 Jan 31.
In this study, we developed a doping technology capable of improving the electrochemical performance, including the rate capability and cycling stability, of P2-type NaFeMnO as a cathode material for sodium-ion batteries. Our approach involved using titanium as a doping element to partly substitute either Fe or Mn in NaFeMnO. The Ti-substituted NaFeMnO shows superior electrochemical properties compared to the pristine sample. We investigated the changes in the crystal structure, surface chemistry, and particle morphology caused by Ti doping and correlated these changes to the improved performance. The enhanced rate capability and cycling stability were attributed to the enlargement of the NaO slab in the crystal structure because of Ti doping. This promoted Na-ion diffusion and prevented the phase transition from the P2 to the OP4/″Z″ structure.
在本研究中，我们开发了一种掺杂技术，该技术能够改善作为钠离子电池阴极材料的P2型NaFeMnO的电化学性能，包括倍率性能和循环稳定性。我们的方法是使用钛作为掺杂元素，部分替代NaFeMnO中的Fe或Mn。与原始样品相比，Ti取代的NaFeMnO表现出优异的电化学性能。我们研究了Ti掺杂引起的晶体结构、表面化学和颗粒形态的变化，并将这些变化与性能的改善相关联。倍率性能和循环稳定性的提高归因于Ti掺杂导致晶体结构中NaO板层的扩大。这促进了Na离子扩散并防止了从P2到OP4/″Z″结构的相变。
