Anionic Redox Reactions in Manganese-Based Binary Layered Oxides for Advanced Sodium-Ion Batteries,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.)

Anionic Redox Reactions in Manganese-Based Binary Layered Oxides for Advanced Sodium-Ion Batteries
Chemistry of Materials ( IF 7.2 ) Pub Date : 2020-06-11 , DOI: 10.1021/acs.chemmater.0c00415
Duho Kim ₁ , Jangmin Lee ₁

Affiliation

Oxygen 2p-electron, unhybridized with transition metals (TMs), is a critical species for the generation of an anion-based redox reaction of O^2–/O^– for high-energy-density cathodes in lithium-ion and sodium-ion batteries (LIBs and SIBs, respectively). More importantly, oxygen redox activity has been highlighted as a breakthrough to increase the intrinsic low redox potential for SIBs because its reaction theoretically and experimentally occurs at ≈4.2 V versus Na⁺/Na. Here, we present in detail the thermodynamic, structural, and chemical origins of stabilized Ni²⁺ (redoxable) and Mn⁴⁺ (nonredoxable), determined by the different electronegativity values in Mn-based binary layered oxides, without excess monovalent element in the TM layer, for the rational use of an anion-based redox reaction. The Ni solubility into Na[Mn_1–xNi_x]O₂ has the highest value at x = 0.5 owing to the decrease in Mn³⁺ instability with the maximally stabilized Ni²⁺, which is understood by the thermodynamic mixing enthalpy value, M–O (M: Mn and Ni) and Na–O bonding lengths, and qualitative and quantitative electronic structure investigations. Utilizing the cumulative redox reaction, combined with the cationic and anionic species, the thermodynamically stabilized Na[Mn_0.5Ni_0.5]O₂ is predicted to show a double redox reaction of Ni²⁺/Ni⁴⁺ and a subsequent anion-based redox reaction of O^2–/O^n– combined with a partial Ni redox contribution, indicating a much higher redox potential behavior as compared with that of a single redox reaction of Mn³⁺/Mn⁴⁺ in NaMnO₂. Our more concrete understanding of the thermodynamic, structural, and chemical origins, coupled with the stabilized Ni²⁺ (variant) and Mn⁴⁺ (invariant) species for redox reactions in the energetics in crystal field theory, is a critical factor in boosting the use of the Mn-based layered oxides and overcoming the limitations of low energy density for SIBs.

中文翻译：

用于高级钠离子电池的锰基二元氧化物中的阴离子氧化还原反应

氧的2p电子，与过渡金属（TMS）未杂交，是用于将基于阴离子氧化还原反应的产生的关键物种ö ^{2- /} O ^-用于在锂离子和钠离子电池的高能量密度的阴极（分别为LIB和SIB）。更重要的是，氧气氧化还原活性已被认为是增加SIBs固有的低氧化还原电位的突破，因为它的反应在理论上和实验上相对于Na ⁺ / Na约为4.2V 。在这里，我们详细介绍了稳定的Ni ²⁺（可氧化）和Mn ⁴⁺的热力学，结构和化学起源。（不可氧化还原），是由Mn基二元层状氧化物中不同的电负性值确定的，TM层中没有过量的一价元素，用于合理使用基于阴离子的氧化还原反应。Ni在Na [Mn _{1– x} Ni _x ] O ₂中的溶解度在x = 0.5时具有最高值，这是因为随着最大稳定的Ni 2 ⁺，Mn ³⁺不稳定性降低，这可以通过热力学混合焓值来理解， M–O（M：Mn和Ni）和Na–O键长，以及定性和定量电子结构研究。利用累积的氧化还原反应，结合阳离子和阴离子物质，热力学稳定的Na [Mn_0.5镍_0.5 ] O ₂被预测为显示Ni的双氧化还原反应²⁺ /镍⁴⁺和随后的基于阴离子氧化还原反应ö ^{2- /} O ^{ñ -}结合的部分的Ni氧化还原贡献，表明高得多的与NaMnO ₂中Mn ³⁺ / Mn ⁴⁺的单个氧化还原反应相比，氧化还原电位行为。我们对热力学，结构和化学起源的更具体的理解，再加上稳定的Ni ²⁺（变体）和Mn ⁴⁺ 晶体场论中高能学中氧化还原反应的（不变）物种是促进使用Mn基层状氧化物并克服SIB的低能量密度限制的关键因素。

更新日期：2020-07-14

点击分享查看原文

点击收藏

阅读更多本刊最新论文本刊介绍/投稿指南11