Kim Soo, Noh Jae-Kyo, Aykol Muratahan, Lu Zhi, Kim Haesik, Choi Wonchang, Kim Chunjoong, Chung Kyung Yoon, Wolverton Chris, Cho Byung-Won
Department of Materials Science and Engineering, Northwestern University , 2220 Campus Drive, Evanston, Illinois 60208, United States.
Center for Energy Convergence Research, Korea Institute of Science and Technology (KIST) , Hwarang-ro 14-gil 5, Seongbuk-gu, Seoul 136-791, Republic of Korea.
ACS Appl Mater Interfaces. 2016 Jan 13;8(1):363-70. doi: 10.1021/acsami.5b08906. Epub 2015 Dec 22.
In this work, we report the electrochemical properties of 0.5Li2MnO3·0.25LiNi0.5Co0.2Mn0.3O2·0.25LiNi0.5Mn1.5O4 and 0.333Li2MnO3·0.333LiNi0.5Co0.2Mn0.3O2·0.333LiNi0.5Mn1.5O4 layered-layered-spinel (LLS) cathode materials prepared by a high-energy ball-milling process. Our LLS cathode materials can deliver a large and stable capacity of ∼200 mAh g(-1) at high voltages up to 4.9 V, and do not show the anomalous capacity increase upon cycling observed in previously reported three-component cathode materials synthesized with different routes. Furthermore, we have performed synchrotron-based in situ X-ray diffraction measurements and found that there are no significant structural distortions during charge/discharge runs. Lastly, we carry out (opt-type) van der Waals-corrected density functional theory (DFT) calculations to explain the enhanced cycle characteristics and reduced phase transformations in our ball-milled LLS cathode materials. Our simple synthesis method brings a new perspective on the use of the high-power LLS cathodes in practical devices.
在本工作中，我们报道了通过高能球磨法制备的0.5Li2MnO3·0.25LiNi0.5Co0.2Mn0.3O2·0.25LiNi0.5Mn1.5O4和0.333Li2MnO3·0.333LiNi0.5Co0.2Mn0.3O2·0.333LiNi0.5Mn1.5O4层状-层状-尖晶石（LLS）正极材料的电化学性能。我们的LLS正极材料在高达4.9 V的高电压下能够提供约200 mAh g(-1)的大且稳定的容量，并且在循环过程中未表现出在先前报道的通过不同路线合成的三元正极材料中观察到的异常容量增加。此外，我们进行了基于同步加速器的原位X射线衍射测量，发现在充放电过程中没有明显的结构畸变。最后，我们进行了（opt型）范德华校正密度泛函理论（DFT）计算，以解释我们球磨的LLS正极材料中增强的循环特性和减少的相变。我们简单的合成方法为高功率LLS正极在实际器件中的应用带来了新的视角。
