Scalable Synthesis of Fe/N-Doped Porous Carbon Nanotube Frameworks for Aqueous Zn-Air Batteries

Thermal-Responsive and Fire-Resistant Materials for High-Safety Lithium-Ion Batteries

As one of the most efficient electrochemical energy storage devices, the energy density of lithium-ion batteries (LIBs) has been extensively improved in the past several decades. However, with increased energy density, the safety risk of LIBs becomes higher too. The frequently occurred battery accidents worldwide remind us that safeness is a crucial requirement for LIBs, especially in environments with high safety concerns like airplanes and military platforms. It is generally recognized that the catastrophic thermal runaway (TR) event is the major cause of LIBs related accidents. Tremendous efforts have been devoted to coping with the TR concerns in LIBs, and thus enhance battery safety. This review first gives an introduction to the fundamentals of LIBs and the origins of safety issues. Then, the authors summarize the recent advances to improve the safety of LIBs with a unique focus on thermal-responsive and fire-resistant materials. Finally, a perspective is proposed to guide future research directions in this field. It is anticipated this review will stimulate inspiration and arouse extensive studies on further improvement in battery safety.

An Efficient Catalyst Derived from Carboxylated Lignin-Anchored Iron Nanoparticle Compounds for Carbon Monoxide Hydrogenation Application

Catalytic activity and target product selectivity are strongly correlated to the size, crystallographic phase, and morphology of nanoparticles. In this study, waste lignin from paper pulp industry is employed as the carbon source, which is modified with carboxyl groups at the molecular level to facilitate anchoring of metals, and a new type of carbon-based catalyst was obtained after carbonization. As a result, the size of the metal particles is effectively controlled by the chelation between -COO- and Fe3+. Furthermore, Fe/CM-CL with a particle size of 1.5-2.5 nm shows excellent catalytic performance, the conversion of carbon monoxide reaches 82.3%, and the selectivity of methane reaches 73.2%.

Hierarchically Porous Co/Cox My (M = P, N) as an Efficient Mott-Schottky Electrocatalyst for Oxygen Evolution in Rechargeable Zn-Air Batteries

Tailoring composition and morphology of electrocatalysts is of great importance in improving their catalytic performance. Herein, a salt-templated strategy is proposed to construct novel multicomponent Co/Co_x M_y (M = P, N) hybrids with outstanding electrocatalytic performance for the oxygen evolution reaction (OER). The obtained Co/Co_x M_y hybrids present porous sheet-like architecture consisting of many hierarchical secondary building-units. The synthetic strategy depends on a facile and effective dissolution-recrystallization-pyrolysis process under NH₃ atmosphere of the precursors, which does not involve any surfactant or long-time hydrothermal pretreatment. That is different from the conventional methods for the synthesis of hierarchical nitrides/phosphides. Benefitting from unique composition/structure-dependent merits, the Co/Co_x M_y hybrids as a typical Mott-Schottky electrocatalyst exhibit good OER performance in an alkaline medium compared with their counterparts, as evidenced by a low overpotential of 334 mV at 10 mA cm^-2 and a small Tafel slope of 79.2 mV dec^-1 , as well as superior long-term stability. More importantly, the Co/Co_x M_y +Pt/C achieves higher voltaic efficiency and several times longer cycle life than conventional RuO₂ +Pt/C catalysts in rechargeable Zn-air batteries. It is envisioned that the present work can provide a new avenue for the development of Mott-Schottky electrocatalysts for sustainable energy storage.