The booming electric vehicle industry continues to place higher requirements on power batteries related to economic-cost, power density and safety. The positive electrode materials play an important role in the energy storage performance of the battery. The nickel-rich NCM (LiNi_xCo_yMn_zO₂ with x + y + z = 1) materials have received increasing attention due to their high energy density, which can satisfy the demand of commercial-grade power batteries. Prominently, single-crystal nickel-rich electrodes with s unique micron-scale single-crystal structure possess excellent electrochemical and mechanical performance, even when tested at high rates, high cut-off voltages and high temperatures. In this review, we outline in brief the characteristics, problems faced and countermeasures of nickel-rich NCM materials. Then the distinguishing features and main synthesis methods of single-crystal nickel-rich NCM materials are summarized. Some existing issues and modification methods are also discussed in detail, especially the optimization strategies under harsh conditions. Finally, an outlook on the future development of single-crystal nickel-rich materials is provided. This work is expected to provide some reference for research on single-crystal nickel-rich ternary materials with high energy density, high safety levels, long-life, and their contribution to sustainable development.

Biomass-derived porous carbon has gained significant attention as a cost-effective and sustainable material in non-noble metal carbon-based electrocatalysts for the oxygen reduction reaction (ORR). However, during the preparation of transition metal catalysts based on biomass-derived porous carbon, the agglomeration of transition metal atoms often occurs, leading to a notable decline in catalytic activity. In this study, we present a straightforward synthetic approach for the preparation of nitrogen-enriched soybean-derived porous carbon (Co@SP-C-a) as an electrocatalyst for the ORR. To achieve this, we employed a two-step method. In the first step, a chemical activator (KCl) was utilized to enhance the porosity of the self-doped nitrogen biomass carbon material. In the second step, a constant pressure drop funnel technique was employed to uniformly disperse bimetal cobalt/zinc-based zeolitic imidazolium frameworks (ZIF-L and ZIF-67) containing different metal ions (Zn²⁺ and Co²⁺) into the activated biomass carbon material. Subsequent high-temperature calcination of the ZIF-L and ZIF-67@SP-C-a composite precursor yielded the Co@SP-C-a catalyst. The obtained catalyst exhibited remarkable ORR activity in an alkaline solution (E_onset = 0.89 V, E_1/2 = 0.83 V, J_L = −6.13 mA·cm⁻²) and exceptional long-term stability. This study presents an effective strategy to prevent the agglomeration of metal nanoparticles when integrating them with biomass-based carbon materials, thus leading to enhanced catalytic performance.

Proton exchange membrane fuel cells (PEMFCs) have been widely studied as an efficient and environmentally friendly energy conversion technology in recent years. However, the high cost, easy poisoning and complex synthesis methods of noble metal catalysts have hindered their commercialization. Therefore, in this paper, a non-noble metal composite catalyst CuFeCo/C for the oxygen reduction reaction (ORR) was prepared by using a facile liquid-phase reduction method. The ORR kinetic performance of CuFeCo/C was evaluated by cyclic voltammetry (CV), linear sweep voltammetry (LSV) and rotating ring-disk electrode (RRDE) tests. The results show that the oxygen reduction peak of CuFeCo/C appears at about 0.64 V, the half-wave potential is about 0.73 V, the limiting current density is about −16.51 A·m⁻², and the Tafel slope is about −0.08. The 10,800 s chronoamperometry test shows that the catalyst has a very good long-term cycle stability. This indicates that the CuFeCo/C composite catalyst has strong stability, good conductivity and ORR catalytic activity under alkaline conditions, which can promote the large-scale commercial application of PEMFCs.

Cu₂ZnSnS₄(CZTS) has attracted a lot of attention recently as a promising absorber layer material in a heterojunction solar cell. In this work, the Zn_1-xMg_xO material is substituted for CdS due to its abundant and nontoxic consisting elements. We have studied the band gaps of Zn_1-xMg_xO alloys with different values of x and the band offsets at Zn_0.75Mg_0.25O/CZTS heterointerface based on the first-principles and pseudopotential calculation method. The band gaps enhance linearly with the increasing values of x. The total density of state and local density of state of each atom in Zn_0.75Mg_0.25O/CZTS supercell are calculated. We predict that the heterojunction of Zn_0.75Mg_0.25O/CZTS is a type II heterointerface with a 0.2eV of conduction band offset, during which the conduction band minimum of Zn_0.75Mg_0.25O is lower than that of CZTS.