New approaches to consider electrical properties, band gaps and rate capability of same-structured cathode materials using density of states diagrams: Layered oxides as a case study

Defect-mediated Jahn-Teller effect in layered LiNiO2

“…1b). The spin-up e g band lies on the Fermi level and exhibits a conducting behavior, which is consistent with the previous theoretical studies and contrary to the experimental semiconductor behavior [11][12][13][14][16][17][18][19][20]. The extra-Ni model (Li 26 Ni)Ni 27 O 54 also exhibits a conducting behavior.…”

“…However, the crystallographic and electronic structures of LNO remain subjects of considerable controversy. LNO has been experimentally reported to exist in the R m 3 phase [5-9] and exhibit semiconductor behavior with a small band gap [10][11][12][13][14][15], while theoretical studies have reported that stoichiometric R m 3 LNO is a conductor and unstable [16][17][18][19][20][21][22]. Moreover, the Ni ions in LNO are considered as Jahn-Teller (JT)-active Ni 3+ with the electronic configuration of t 2g 6 e g 1 [8,10,12,23].…”

“…The discrepancy between the experimental and theoretical studies has been explained based on phases other than R m 3 [22,[29][30][31], building possible orbital ordering patterns [8,21,30,32], defective structures [33][34][35], time and ordering averages of dynamic stabilization [29,36], and combining theoretical methods [16][17][18][19][20]22,37]; however, few such studies have provided sufficient explanations. The most plausible explanation for this discrepancy was provided by Petit et al [33].…”

An insight into charge/discharge behaviors of lithium/sodium‐sulfur conversion batteries and their similarity to the lithium/sodium‐ion intercalation batteries: Relation of delivered capacity vs current rate

“…[1][2][3] On the other hand, the intercalations are generally lighter in weight, have higher life-cycles, higher voltage, and no/low memory effect. [6][7][8] As a matter of fact, due to the different nature of phase transition mechanisms of the conversion and intercalation batteries, it seems that their relationships, modeling, and understanding of behaviors should be evaluated by different approaches. However, here we propose a similar relationship for both of the battery categories.…”

Boundaries of charge–discharge curves of batteries

“…Voltage–time ( V – T ) or voltage–capacity ( V – C ) behaviours during the charge–discharge processes, as well as their relevant underlying mechanisms, are indeed some of the most important characterization parameters of energy storage devices, namely the intercalation (Li-ion and Na-ion) batteries. 1,6–8…”