<br>了解 Al 和 Mn 掺杂对高镍层状氧化物阴极中 H2-H3 相变的影响,Chemistry of Materials

当前位置： X-MOL 学术 › Chem. Mater. › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

了解 Al 和 Mn 掺杂对高镍层状氧化物阴极中 H2-H3 相变的影响
Chemistry of Materials ( IF 7.2 ) Pub Date : 2024-06-04 , DOI: 10.1021/acs.chemmater.4c01033
J. Brandon Adamo ₁ , Arumugam Manthiram ₁

Affiliation

高镍层状氧化物阴极是下一代锂离子电池（LIB）中很有前景的材料系列。然而，有害的相变和表面不稳定性阻碍了它们的大规模采用。 Al 掺杂和 Mn 掺杂均已被证明可以提高循环性能，但会牺牲初始容量。然而，这些掺杂剂对高压 H2-H3 相变性能的影响仍有待探索。在此，我们研究了Al和Mn掺杂对Li[Ni _0.95 Al _0.05 ]O ₂ 和Li[Ni _0.95 Al _0.05 ]O ₂ 中H2-H3相变的影响 _0.95 Mn _0.05 ]O ₂ 与未掺杂的 LiNiO ₂ (LNO) 相比。我们发现 5% Al 掺杂和 5% Mn 掺杂都抑制和延迟了向更高电压的相变，但似乎对其可逆性的影响很小。我们进一步发现，掺杂剂在经过相变时减少了阻抗随电压的增加，但这样做是以牺牲容量为代价的。循环步进计时电流法表明，与未掺杂的 LNO 相比，Al 和 Mn 均通过 H2-H3 相变提高了倍率性能。这是由于掺杂剂在高充电状态下拓宽了锂扩散通道，这一点已通过 X 射线衍射得到验证。这项工作提供了对 H2-H3 相变的深入了解，这是优化下一代锂离子电池循环方案所必需的，并提高了我们对这些关键能源材料的总体理解。

"点击查看英文标题和摘要"

Understanding the Effects of Al and Mn Doping on the H2–H3 Phase Transition in High-Nickel Layered Oxide Cathodes

High-nickel layered oxide cathodes make up a promising family of materials for next-generation lithium-ion batteries (LIBs). Deleterious phase transitions and surface instabilities, however, have hindered their mass adoption. Al doping and Mn doping have both been shown to improve cyclability at the expense of the initial capacity. However, the effects of these dopants on the performance of the high-voltage H2–H3 phase transition remain unexplored. Herein, we examine the effects of Al and Mn doping on the H2–H3 phase transition in Li[Ni_0.95Al_0.05]O₂ and Li[Ni_0.95Mn_0.05]O₂ in comparison to that in undoped LiNiO₂ (LNO). We find that 5% Al doping and 5% Mn doping both suppress and delay the phase transition to a higher voltage but appear to affect its reversibility only minimally. We further find that the dopants reduce the increase in impedance with voltage when passing through the phase transition but do so at the expense of capacity. Cyclic step chronoamperometry shows that Al and Mn both improve the rate performance through the H2–H3 phase transition compared to that of undoped LNO. This is attributed to widened lithium diffusion channels at high states of charge enabled by the dopants, which is verified with X-ray diffraction. This work provides insights into the H2–H3 phase transition, necessary for optimized cycling protocols for next-generation LIBs, and improves our general understanding of these crucial energy materials.

更新日期：2024-06-04

点击分享查看原文

点击收藏

阅读更多本刊新发论文本刊介绍/投稿指南