在O3堆积的情形下，采用新的标记符号来描述相变，即问题描述中的H1 H2 H3 M1， 字母表示单个晶胞的对称性信息（H表示六方，M表示单斜），数字表示充电过程中观察到的相顺序，讨论中规定堆积层在ab平面上，c轴垂直于堆积层。

2019年7月15日 · As shows, the poor reversibility of H2-H3 phase transition and gradually loss of H3 phase associated with poor structural stability of NCM, should take responsibility for the faster capacity drop of the NCM sample.

Researchers have also found that the phase transition from H2 to H3 can lead to (003) peaks shifting to higher degrees and that Li-reordering (Li diffusing into Ni 4+-rich sites) can further convert H3 to H3-2 in which the fast shrinkage of the c-axis at potentials above 4.15 V is a clear indication of this phase transition.

2020年5月1日 · NMC622 also undergoes an H2/H3 phase transition upon deeper delithiation to x < 0.28 in Li x Ni 0.6 Mn 0.2 Co 0.2 O 2. A similar analysis can be performed for this two-phase coexistence region, but the predicted critical particle size is larger because H2 and H3 have a smaller misfit strain (ε a = 0.2%, ε c = −1.1%) than the H1/H2 pair (ε ...

2021年9月7日 · The pristine SC-NCM88 and 1% LYTP@SC-NCM88 cathodes all undergo a series of phase transformations from the hexagonal 1 (H1) phase to the hexagonal 3 (H3) phase via a monoclinic (M) and a...

The transition from H2 to H3 under a high voltage regime is mainly attributed to the abrupt shrinkage on the c-axis in the unit cell, resulting in detrimental anisotropic lattice volume changes. In the case of NCM622, the peak of the H2-to-H3 transformation is absent in the phase diagram.

2021年7月13日 · The H2–H3 phase transition peaks, considered as a critical gauge of the rapid capacity fading for Ni-rich layered cathodes, faded differently with cycling, suggesting that different mechanisms govern the capacity fading of S-NCM and P-NCM cathodes.

图2g显示，P-NCM90正极的H2-H3峰强度随循环降低，且极化变大，表明由于H2-H3相变引起的严重体积变化，P-NCM90正极颗粒中形成了大量微裂纹，随之而来的表面杂质的形成使阻抗增加，加速了容量衰减。 相比之下，S-NCM90正极的H2-H3峰衰减速度不如P-NCM90正极，尽管其循环稳定性较差，但在循环过程中没有任何位置变化，表明 S-NCM和P-NCM正极的容量损失机制不同。 无论S-NCM正极中的Ni含量如何，荷电S-NCM正极颗粒中微裂纹的发生率很低。

2024年6月1日 · This study elucidates on the effect of resting NMC811‖Graphite cells in the H2–H3 phase transition potential region on the cycle life of the cells. The results are compared to cells that are cycled to the same SoC cut-off as well as cells that are cycled to 100 % SoC.

2019年5月1日 · The improved reversibility of the H2-H3 phase transitions can not only suppress the generation of microcracks and structural transformations, but also allow continuous high capacity delivery. Consequently, the Ti 4+ doped sample with an optimal content of 5 mol% exhibited excellent cycling performance without sacrificing the capacity.