The utilization of high‐voltage LiCoO2 is imperative to break the bottleneck of the practical energy density of lithium‐ion batteries. However, LiCoO2 suffers from severe structural and interfacial degradation at >4.55 V. Herein, a novel lattice‐matched LiCoPO4 coating is rationally designed for LiCoO2 which works at 4.6 V (vs Li/Li+) or above. This LiCoPO4 coating, derived by an in situ chemical reaction, grows epitaxially on LiCoO2 crystallite with strong bonding and complete coverage to LiCoO2, ensuring a stable cathode–electrolyte interface with fewer side reactions and alleviated intergranular cracking and phase collapse during repeated high‐voltage lithiation/delithiation processes. In addition, the formed strong covalent P–O tetrahedron configuration at the interface effectively decreases the surface oxygen activity of LiCoO2, further suppressing oxygen release and irreversible phase transition. Therefore, the LiCoPO4‐LiCoO2ǁLi cells display excellent capacity retention of 87% after 300 cycles at 4.6 V and stable operation at 4.6 V/55 °C or 4.7 V/30 °C. The strategy of lattice‐matching growth affords a new way to impact the development of high‐voltage LiCoO2 and beyond.

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The design of rare-earth-metal oxide/oxysulfide catalysts with high activity and durability for the oxygen reduction reaction (ORR) is still a grand challenge at present. In this study, Ce-species (CeOS/CeO)/N, S dual-doped carbon (Ce-species/NSC) catalysts with promising oxygen storage/release capacities are prepared at different temperatures (800-1000 °C) to enhance the ORR efficiency. Mechanisms for the effects of temperature on crystalline phase transition between CeO and CeOS and structure evolution of Ce-species/NSCs are inferred to better understand their catalytic activity. Porous CeOS/NSC (950 °C) catalyst as the air-breathing cathode exhibits a maximum power density of 1087.2 mW m, which is higher than those of other Ce-species/NSCs and commercial Pt/C (989.13 mW m) in microbial fuel cells. The decline of the power density of CeOS/NSC (950 °C) cathode is 8.7% after 80 days of operation, which is far lower than that of Pt/C (36.7%). CeOS/NSC (950 °C) has a four-electron selectivity toward the ORR and a low charge-transfer resistance (5.49 Ω), contributing to high ORR activity and durability. The promising ORR catalytic activity of CeOS/NSC (950 °C) is attributed to its high specific surface area (338.9 m g), varied active sites, high electrical conductivity, and sufficient oxygen vacancies in the CeOS skeleton. The high content of Ce in CeOS/NSC (950 °C) facilitates the formation of more oxygen-deficient Ce sites that generate more oxygen vacancies to release/store more oxygen to stabilize the available oxygen for the ORR. Thus, this study provides a new perspective for preparation and application of this new type of the ORR catalyst.

To improve the sluggish kinetics of the methanol oxidation reaction (MOR), one efficient way is to improve the properties of catalyst supports to enhance the activity and durability of Pt-based catalysts.

Binders play a crucial role in the development of silicon (Si) anodes for lithium-ion batteries with high specific energy. The large volume change of Si (∼300%) during repeated discharge and charge processes causes the destruction and separation of electrode materials from the copper (Cu) current collector and ultimately results in poor cycling performance. In the present study, we design and prepare hydrogen-bonding cross-linked thiourea-based polymeric binders (denoted CMC-co-SN) in consideration of their excellent binding interaction with the Cu current collector and low cost as well. The CMC-co-SN binders are formed through in situ thermopolymerization of chain-type carboxymethylcellulose sodium (CMC) with thiourea (SN) in the drying process of Si electrode disks. A tight and physical interlocked layer between the CMC-co-SN binder and Cu current collector is derived from a dendritic nonstoichiometric copper sulfide (Cu x S) layer on the interface and enhances the binding of electrode materials with the Cu current collector. When applying the CMC-co-SN binders to micro- (∼3 μm) (μSi) and nano- (∼50 nm) (nSi) Si particles, the Si anodes exhibit high initial Coulomb efficiency (91.5% for μSi and 83.2% for nSi) and excellent cyclability (1121 mA h g–1 for μSi after 140 cycles and 1083 mA h g–1 for nSi after 300 cycles). The results demonstrate that the CMC-co-SN binders together with a physical interlocked layer have significantly improved the electrochemical performance of Si anodes through strong binding forces with the current collector to maintain electrode integrity and avoid electric contact loss.

Li‐ion Batteries In article number 2200197, Yong Yang and co‐workers report a novel lattice‐coherent LiCoPO4 coating on LiCoO2 (LCO), derived by the in‐situ chemical reaction of Co(OH)2 and LiH2PO4, that can effectively alleviate irreversible structure transition and resist electrolyte corrosion, ensuring a high‐voltage LCO electrode (≥4.6V), and stable operation in portable electronic devices, such as mobile phones, computers, tablets, etc., to meet the high‐energy demand of the coming 5G era.

Methanol oxidation reaction (MOR) efficiency is lowered by poor COads-tolerance and structural stability of Pt-based catalysts. Herein, single crystal Ni3S2 nanorods (with exposed {110} high-index facets) coated with MoS2 particles are grown on nickel foam (MoS2/Ni3S2-nrs/NF) as a low-loading Pt support/cocatalyst (Pt, 0.5 wt %), which not only enhances anti-COads poisoning capacity but also extremely improves the structure stability of the catalyst. Pt/MoS2/Ni3S2-nrs/NF catalyst exhibits a mass activity of 805.4 mA mgPt –1, which is 1.97 times higher than that of commercial Pt/C (10 wt %). It also shows an excellent cyclic durability with 4.6% decline (Pt/C, 40.2%) after 28 h. Electrochemcial tests and theoretical calculations (DFT) reveal that the excellent MOR activity and durability of Pt/MoS2/Ni3S2-nrs/NF are primarily attributed to the close binding effects among Pt, MoS2, and Ni3S2-nrs. Theoretical calculations show that, when Pt nanoparticles deposit on the preconstructed MoS2/Ni3S2-nrs hybrid, they preferentially attach to the single crystal Ni3S2-nrs rather than MoS2 particles. These heterostructures can offer sufficient active sites in radial direction, which energetically promote the charge transfer along axial dimension. Sufficient Mo–S x edge (interface) sites facilitate OHads generation from H2O decomposition. Meanwhile, OHads can fast react with/eliminate CO-species on MoS2/Ni3S2-nrs attracted from Pt active-sites. Therefore, MoS2/Ni3S2-nrs/NF as a promising MOR support/cocatalyst provides unique perspectives for high-efficient utilization of Pt.

The surface chemistry of garnet electrolyte is sensitive to air exposure. The poor LLZO/Li interface caused by Li2CO3/LiOH contaminants on garnet electrolyte surface easily induces large interfacial resistance resulting in the growth of Li dendrites. Herein, a versatile modification strategy is designed to convert the contaminants on Li6.4La3Zr1.4Ta0.6O12 (LLZTO) surface into a LiF and Li2PO3F‐rich lithiophilic interface by targeted chemical reactions at the interface between LiPO2F2 and Li2CO3/LiOH. The newly formed LiF‐Li2PO3F interfacial layer not only facilitates the interface wettability between Li and LLZTO, but also helps to resist corrosion of the LLZTO surface by moisture in the air. The Li|LiF&Li2PO3F‐LLZTO|Li symmetric cell exhibits a low interfacial resistance of 5.1 Ω cm2 and ultrastable galvanostatic cycling, over 1500 h at 0.6 mA cm−2 and over 70 h at 1.0 mA cm−2. In addition, LiCoO2|LiF&Li2PO3F‐LLZTO|Li hybrid solid‐state full cells display high initial specific capacity of 192 mAh g−1 at 0.1 C, and excellent cycling stability with a capacity retention over 76% even after 1000 cycles at 0.5 C at a high cut‐off voltage of 4.5 V. This study provides a simple and practical strategy for the feasibility of the application of high‐voltage cathodes in this modified garnet all‐solid‐state batteries.