Ab initio determination of a simultaneous dual-ion charging mechanism for Ni 0.25 Mn 0.75 O 2 through redox reactions of Ni 2+ /Ni 4+ and O 2- /O -
Ab initio determination of a simultaneous dual-ion charging mechanism for Ni 0.25 Mn 0.75 O 2 through redox reactions of Ni 2+ /Ni 4+ and O 2- /O -
复制标题
通过 Ni 2 /Ni 4 和 O 2- /O - 的氧化还原反应从头确定 Ni 0.25 Mn 0.75 O 2 的同时双离子充电机制
DOI：
10.1039/d2ta03938a
复制
发表时间：
2022
影响因子：
11.9
通讯作者：
Smeu, Manuel
中科院分区：
文献类型：
--
作者：
Shepard, Robert;Brennan, Scott;Juran, Taylor R;Young, Joshua;Smeu, Manuel
近年来，层状过渡金属氧化物作为二次电池正极材料的极限得到了极大的发展。对于许多材料来说，总体能力已经达到了最终的理论值，这一点尤其如此。在充电过程中增加这一容量的一个途径是阳离子脱嵌后的阴离子插层。本文用密度泛函理论研究了P3-Na0.5Ni0.25Mn0.75O2正极材料通过阳离子(Na)脱嵌和阴离子(ClO4)插层的充电机理。计算结果证实了阴离子插层提高容量的实验结果(135mA h g−1至180 mA h g−1)。研究表明，正极材料的主要充电机制是同时发生阳离子脱嵌/阴离子插层过程，正极材料中发生了Ni2+/Ni4+和O2−/O−的电荷补偿反应。为了阐明这一同步过程，提出了一种计算确定阴离子电压的新方法，其中必须考虑完全的电解液相互作用。基于这一结果，人们认为，同时的阳离子脱嵌/阴离子插层机制为发现下一代二次电池提供了一条潜在的途径。
Over recent years, great efforts have been made to push the limits of layered transition metal oxides for secondary battery cathodes. This is particularly true for overall capacity, which has reached a terminal theoretical value for many materials. One avenue for increasing this capacity during charging is the intercalation of anions post cation deintercalation. This work investigates the charging mechanism of the P3-Na0.5Ni0.25Mn0.75O2 cathode material through cation (Na) deintercalation and anion (ClO4) intercalation by means of density functional theory. The calculations corroborate experimental findings of increased capacity (135 mA h g−1 to 180 mA h g−1) through the intercalation of anions. However, this work demonstrates that a process of simultaneous cation deintercalation/anion intercalation is the primary charging mechanism, with charge compensation reactions of Ni2+/Ni4+ and O2−/O− occurring within the cathode material. To elucidate this simultaneous process, a novel method for computationally determining anion voltage in which one must consider full electrolyte interactions is proposed. Based on the results, it is believed that a simultaneous cation deintercalation/anion intercalation mechanism provides one potential avenue for the discovery of the next generation of secondary batteries.