A considerable amount of platinum (Pt) is required to ensure an adequate rate for the oxygen reduction reaction (ORR) in fuel cells and metal‐air batteries. Thus, the implementation of atomic Pt catalysts holds promise for minimizing the Pt content. In this contribution, atomic Pt sites with nitrogen (N) and phosphorus (P) co‐coordination on a carbon matrix (PtNPC) are conceptually predicted and experimentally developed to alter the d‐band center of Pt, thereby promoting the intrinsic ORR activity. PtNPC with a record‐low Pt content (≈0.026 wt %) consequently shows a benchmark‐comparable activity for ORR with an onset of 1.0 VRHE and half‐wave potential of 0.85 VRHE. It also features a high stability in 15 000‐cycle tests and a superior turnover frequency of 6.80 s−1 at 0.9 VRHE. Damjanovic kinetics analysis reveals a tuned ORR kinetics of PtNPC from a mixed 2/4‐electron to a predominately 4‐electron route. It is discovered that coordinated P species significantly shifts d‐band center of Pt atoms, accounting for the exceptional performance of PtNPC.

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Spin state transition and intermetallic charge transfer can essentially change material structural and physical properties with a fashion of excluding external chemical doping. However, these two effects have rarely been found to occur sequentially in a specific material. In this article, we show the realization of these two phenomena in a perovskite oxide PbCoO3 with a simple ABO3 composition under high pressure. PbCoO3 possesses a peculiar A-and B-site ordered charge distribution Pb 2+ Pb 4+ 3Co 2+ 2Co 3+ 2O12 with insulating behavior at ambient conditions. The high spin Co 2+ gradually changes to low spin with increasing pressure up to about 15 GPa, leading to the anomalous increase of resistance magnitude. Between 15 GPa and 30 GPa, the intermetallic charge transfer occurs between Pb 4+ and Co 2+ cations. The accumulated charge-transfer effect triggers a metal-insulator transition as well as a first-order structural phase transition toward a Tetra.-I phase at the onset of ~20 GPa near room temperature. On further compression over 30 GPa, the charge transfer completes, giving rise to another first-order structural transformation toward a Tetra.-II phase and the reentrant electrical insulating behavior.

Ni-rich high-energy-density lithium ion batteries pose great risks to safety due to internal short circuits and overcharging; they also have poor performance because of cation mixing and disordering problems. For Ni-rich layered cathodes, these factors cause gas evolution, the formation of side products, and life cycle decay. In this study, a new cathode electrolyte interphase (CEI) for Ni2+ self-oxidation is developed. By using a branched oligomer electrode additive, the new CEI is formed and prevents the reduction of Ni3+ to Ni2+ on the surface of Ni-rich layered cathode; this maintains the layered structure and the cation mixing during cycling. In addition, this new CEI ensures the stability of Ni4+ that is formed at 100% state of charge in the crystal lattice at high temperature (660 K); this prevents the rock-salt formation and the over-reduction of Ni4+ to Ni2+. These findings are obtained using in situ X-ray absorption spectroscopy, operando X-ray diffraction, operando gas chromatography–mass spectroscopy, and X-ray photoelectron spectroscopy. Transmission electron microscopy reveals that the new CEI has an elliptical shape on the material surface, which is approximately 100 nm in length and 50 nm in width, and covers selected particle surfaces. After the new CEI was formed on the surface, the Ni2+ self-oxidation gradually affects from the surface to the bulk of the material. It found that the bond energy and bond length of the Ni–O are stabilized, which dramatically inhibit gas evolution. The new CEI is successfully applied in a Ni-rich layered compound, and the 18650- and the punch-type full cells are fabricated. The energy density of the designed cells is up to 300 Wh/kg. Internal short circuit and overcharging safety tests are passed when using the standard regulations of commercial evaluation. This new CEI technology is ready and planned for future applications in electric vehicle and energy storage.