Jingyu Sun

The imminent retirement of large batches of lithium‐ion batteries poses a critical challenge to sustainable resource management. While present recycling technologies have demonstrated certain advantages over conventional metallurgical methods, the comprehensive assessment of their environmental impacts has introduced additional requirements. These include adherence to the principles of closed‐loop processing, minimized waste streams, and high‐value‐added recovery. Herein, we offer a summarizing framework that emphasizes the integrated utilization of spent batteries, thereby shifting the research focus from maximizing extraction efficiency toward achieving holistic sustainability. By analyzing the evolution of reutilization strategies, we identify that complex separation processes generate nontrivial carbon footprints and water consumption. This review consolidates these critical aspects, with the aim of encouraging a more balanced perspective that considers both material recovery efficiency and battery upcycling potential.

Cu acts as a local electronic modulator in FeCoNi-derived catalysts, enhancing early polysulfide-conversion kinetics without improving long-term retention.

Aqueous Zn metal batteries are promising candidates for large‐scale energy storage, yet their practical deployment is hindered by poor Zn reversibility. Although crystallographic engineering can improve Zn electrochemistry, the precise fabrication of single‐crystal Zn electrodes with full‐dimensional crystallographic coherence remains elusive. Here we report a remote electro‐epitaxy (REE) strategy to render high‐quality single‐crystal Zn electrodes. Using monolayer graphene‐skinned Cu(111) substrate as the epitaxial current collector, REE manages to preserve perfect crystallographic inheritance through substrate‐potential transmission and accommodate lattice mismatch via interfacial strain relaxation, which is evidenced by theoretical and instrumental characterizations. As a result, the Zn(002) deposits with uniform out‐of‐plane crystallographic orientation, in‐plane crystallographic coherence, and through‐thickness crystallographic continuity are achieved on both centimeter‐scale foils and 4‐inch wafer substrates. The resulting electrodes warrant reversible Zn plating/stripping behavior, enhanced stability under elevated depth‐of‐discharge conditions, and successful implementation in Ah‐scale pouch cells competing the state‐of‐the‐art. Beyond Zn, our strategy is extendable to a multitude of metals, offering a scalable pathway toward single‐crystal electrode fabrication for emerging energy storage.

The rational design of solid‐state electrolytes (SSEs) with high ionic conductivity, interfacial robustness, and thermal stability remains a critical challenge for lithium metal batteries (LMBs). Herein, we established the crystal‐transformed hydrogen‐bonded organic framework/trinuclear Cu cluster organic framework heterostructures (HOFa/TrCuMOF ₈ ) as thermally stable SSEs for LMBs. The crystal‐transformed HOF/MOF heterostructure constructs continuous low‐energy Li ⁺ transport pathways, while the pendant ‐CH ₃ with strong steric hindrance induces anion adsorption to effectively suppress TFSI ⁻ migration. Meanwhile, coordination‐confined TrCu synergizes with imine (C = N) groups to create a dynamically polarized local electronic environment through Li ⁺ ‐induced charge redistribution, thereby promoting selective Li ⁺ transport. Consequently, the HOFa/TrCuMOF ₈ SSEs deliver a high Li ⁺ transference number (0.94) and ionic conductivity (2.7 mS cm ⁻¹ at 30°C). Compared with polypropylene (PP) separators, the flexible HOFa/TrCuMOF ₈ SSEs maintain structural integrity at high temperatures (180°C), effectively suppressing electrolyte shrinkage and thermal short‐circuit propagation. The assembled Li|HOFa/TrCuMOF ₈ SSEs|LiFePO ₄ LMBs achieve 97.8% capacity retention after 1000 cycles at 2 C and maintain stable cycling even at 100°C. Remarkably, the Li|HOFa/TrCuMOF ₈ SSEs|NCM811 pouch cell exhibits an impressive energy density of 259.4 Wh kg ⁻¹ with enhanced thermal safety. This work provides a crystal‐transformation strategy for engineering HOF/MOF heterostructures toward thermally stable solid‐state lithium batteries.

Electrocatalytic nitrogen reduction reaction (eNRR) under ambient conditions is a promising route for sustainable ammonia synthesis, yet its progress is fundamentally limited by the inertness of N≡N bonds and the lack of robust, selective catalysts. Here, we report the first synthesis of a rutile‐structured high‐entropy oxynitride (HEON, CoFeTiVSnON). By leveraging the mixing entropy of five metal elements and dual anion regulation, HEON achieves dynamically regenerable nitrogen vacancies, and a tunable electronic structure. Operando spectroscopic investigations and density functional theory (DFT) calculations reveal that HEON uniquely activates N ₂ via a stabilized vacancy‐mediated quasi Mars‐van Krevelen (MvK) mechanism, wherein nitrogen vacancies directly participate in the catalytic cycle, enabling continuous vacancy formation and healing. Correspondingly, the NH ₃ poisoning and vacancy depletion issues that plague conventional binary nitrides have been circumvented whilst breaking linear scaling relationship of intermediate adsorption. The HEON catalyst delivers a high NH ₃ yield rate of 159.2 µg h ⁻¹ mg _cat. ⁻¹ and a Faradaic efficiency of 46.6% at −0.5 V vs. RHE, with good structural stability over extended operation. Our work establishes high‐entropy oxynitrides as a transformative platform for multi‐step electrocatalysis, and provides mechanistic insights for the rational design of catalysts stabilized by high entropy effects.

Electrochemical nitrate reduction to ammonia is attractive for green fertilizer synthesis and pollution remediation, yet its performance is normally hindered by the mismatched generation and consumption of active hydrogen (*H). Here, we engineer the planar chloride coordination to break the local symmetry of Cu single atoms over oxygen‐deficient WO _3‐x , forming Cu ₁ Cl–WO _{3‐ x} with Cu–O/Cl and Cu–Cl–W motifs to enable dual interfacial relay of *H and *NO ₂ derived intermediates. The Cu ₁ Cl–WO _{3‐ x} catalyst achieves an NH ₃ Faradaic efficiency of 99.7% at −0.8 V versus the reversible hydrogen electrode and delivers an NH ₃ yield rate up to 63.6 mg h ⁻¹ cm ⁻² at −0.9 V with stable operation. In situ electrochemical characterization and theoretical calculations reveal that the asymmetric Cu–Cl–W interface promotes water dissociation and *H relay, while facilitating thermodynamically favorable *NO ₂ relocation and subsequent hydrogenation, thereby shifting the potential‐determining step and lowering the overall energy barrier. This dual‐relay strategy might offer a generic route toward efficient NO ₃ ⁻ ‐to‐NH ₃ electrosynthesis.

Electrochemical nitrate reduction to ammonia is attractive for green fertilizer synthesis and pollution remediation, yet its performance is normally hindered by the mismatched generation and consumption of active hydrogen (*H). Here, we engineer the planar chloride coordination to break the local symmetry of Cu single atoms over oxygen‐deficient WO _3‐x , forming Cu ₁ Cl–WO _{3‐ x} with Cu–O/Cl and Cu–Cl–W motifs to enable dual interfacial relay of *H and *NO ₂ derived intermediates. The Cu ₁ Cl–WO _{3‐ x} catalyst achieves an NH ₃ Faradaic efficiency of 99.7% at −0.8 V versus the reversible hydrogen electrode and delivers an NH ₃ yield rate up to 63.6 mg h ⁻¹ cm ⁻² at −0.9 V with stable operation. In situ electrochemical characterization and theoretical calculations reveal that the asymmetric Cu–Cl–W interface promotes water dissociation and *H relay, while facilitating thermodynamically favorable *NO ₂ relocation and subsequent hydrogenation, thereby shifting the potential‐determining step and lowering the overall energy barrier. This dual‐relay strategy might offer a generic route toward efficient NO ₃ ⁻ ‐to‐NH ₃ electrosynthesis.

Mechanochemistry uses mechanical force to convert solid wastes and gaseous feedstocks into high-value chemicals, offering a route for environmental remediation and resource recovery.

Potassium (K) metal anodes suffer from uncontrolled solid electrolyte interphase evolution and isolated K accumulation, greatly hindering the construction of practical anode-free batteries. To date, systematic investigations on K stripping behavior and isolated K formation, despite being fundamentally important, are still lacking. Here, we develop an axially coordinated single-atom iron (Fe) anchored on hollow carbon bowls to synergize promoted K desorption and stress-adaptive ion transport. Serving as current collector modification, the FeN ₄ O ₂ moiety optimizes K adsorption/desorption strength, regulates FSI ⁻ decomposition, and suppresses electronically isolated K. Meanwhile, the mechanically compliant carbon-bowl scaffold mitigates volumetric strain during cycling, preserving interfacial integrity and accelerating desorption at the stripping frontier. Multimodal evidence from cryo–transmission electron microscopy, x-ray photoelectron spectroscopy depth profile, and theoretical calculations collectively reveals a bidirectional regulation to enhance both deposition uniformity and stripping reversibility. The anode-free K metal full cell delivers nearly 100 milliampere-hours per gram over 200 cycles at 200 milliamperes per gram, readily rivaling the state-of-the-art counterparts.