LiNi_0.5Mn_1.5O₄ (LNMO) cathode active materials for lithium‐ion batteries have been investigated for over 20 years. Despite all this effort, it has not been possible to transfer their favorable properties into applicable, stable battery cells. To make further progress, the research perspective on these spinel type materials needs to be updated and a number of persisting misconceptions on LNMO have to be overcome. Therefore, the current knowledge on LNMO is summarized and controversial points are addressed by detailed considerations on the composition and crystallography of LNMO. The findings are supported by an in‐situ high temperature X‐ray diffraction study and the investigation of four different types of LNMO materials, including Mn(III) rich ordered LNMO, and disordered LNMO with low Mn(III) content. It is shown that the importance of cation order is limited to a small composition range. Furthermore, new evidence contradicting the idea of oxygen defects in LNMO is presented and an enhanced classification of LNMO based on the Ni content of the spinel phase is proposed. Moreover, a balanced chemical equation for the formation of LNMO is presented, allowing for comprehensive calculations of key properties of LNMO materials. Finally, suitable target compositions and calcination programs are suggested to obtain better LNMO materials.

Tuning of relaxation of magnetisation through 3d metal ion variations in 3d₂Dy₂ butterflies.

The modulation of the magnetic anisotropy using the electronic features of the ligands was monitored by performing magnetic, spectroscopic and theoretical studies on a series of {Fe₂Dy₂} coordination clusters.

Using hydrogen peroxide (H₂O₂), a novel approach was applied for the synthesis of LiNi_0.5Mn_1.5O₄ (LNMO) coated with Li₃PO₄ and doped with Al³⁺ and Ti⁴⁺ ions. The reaction between LNMO and H₂O₂ resulted in particles with a partially damaged surface. If the same reaction is done in the presence of lithium, aluminum, titanium, and phosphate ingredients, then all particle facets are intact and show no sign of destruction. It appears that the H₂O₂ decomposition activates the LNMO surface, generating perfect conditions for the homogeneous deposition of the Li, Al, Ti, and phosphate ions. Electrochemical investigations show a very slow fading process during the cycling, and even after more than 500 cycles, the obtained cathode material shows a high specific capacity of 127 mAh g^–1 (at 1 C) (∼98% capacity retention) and an excellent Coulombic efficiency (99.5%).