Division of Chemical Sciences and Engineering, Argonne National Laboratory, Argonne, Illinois 60439, USA.
1] Division of Chemical Sciences and Engineering, Argonne National Laboratory, Argonne, Illinois 60439, USA [2] Department of Chemistry, Key Laboratory of Organic Optoelectronics and Molecular Engineering, Tsinghua University, Beijing 100084, China.
Nat Commun. 2014 Dec 16;5:5693. doi: 10.1038/ncomms6693.
The capacity fade of lithium manganate-based cells is associated with the dissolution of Mn from cathode/electrolyte interface due to the disproportionation reaction of Mn(III), and the subsequent deposition of Mn(II) on the anode. Suppressing the dissolution of Mn from the cathode is critical to reducing capacity fade of LiMn2O4-based cells. Here we report a nanoscale surface-doping approach that minimizes Mn dissolution from lithium manganate. This approach exploits advantages of both bulk doping and surface-coating methods by stabilizing surface crystal structure of lithium manganate through cationic doping while maintaining bulk lithium manganate structure, and protecting bulk lithium manganate from electrolyte corrosion while maintaining ion and charge transport channels on the surface through the electrochemically active doping layer. Consequently, the surface-doped lithium manganate demonstrates enhanced electrochemical performance. This study provides encouraging evidence that surface doping could be a promising alternative to improve the cycling performance of lithium-ion batteries.
尖晶石锰酸锂的容量衰减与 Mn 从正极/电解液界面溶解有关，这是由于 Mn(III)的歧化反应，随后 Mn(II)在阳极上沉积。抑制 Mn 从正极溶解对于减少尖晶石锰酸锂电池的容量衰减至关重要。在这里，我们报告了一种纳米级的表面掺杂方法，最大限度地减少了锰的溶解。该方法通过阳离子掺杂稳定尖晶石锰酸锂的表面晶体结构，同时保持了体相尖晶石锰酸锂的结构，从而利用了体相掺杂和表面包覆方法的优势，通过电化学活性掺杂层在保持离子和电荷传输通道的同时，保护体相尖晶石锰酸锂免受电解液腐蚀。因此，表面掺杂的尖晶石锰酸锂表现出增强的电化学性能。这项研究提供了令人鼓舞的证据，表明表面掺杂可能是一种有前途的替代方法，可以提高锂离子电池的循环性能。
