Huaneng Clean Energy Research Institute

The simple superposition of multiple gradient structures in three-dimensional (3D) Li anodes can, in principle, integrate the advantages of individual gradients to further regulate Li deposition. However, this “mere superposition” approach often fails to deliver satisfactory cycling stability, and no definitive guideline for achieving true gradient synergistic effects is available. Here, we propose that enhancing the all-space Li+ transport kinetics should serve as the core principle for 3D Li anode gradients designing. Through a facile thermal-compounding process, a 50 μm-thick Li–Mg–Sn alloy film and carbon cloth (CC) sheet are tightly integrated on the stainless-steel substrate at elevated temperature, forming a lithiophilically modified carbon fiber skeleton. Simultaneously, a co-originated dual-gradient structure─comprising pore-size gradient and ion-transport-pathway gradient─is formed in situ within the skeleton. The two ion-transport pathways at the bottom offset the limited Li+ diffusion in small pores, boosting all-space Li+ transport kinetics throughout the 3D host and guiding preferential Li deposition at the electrode bottom. The symmetric cell sustains cycling stability over 5000 h with an ultralow polarization voltage of ∼14 mV at 1 mA cm–2/1 mAh cm–2 and >1200 h at 3 mA cm–2/3 mAh cm–2. When paired with a LiFePO4 cathode (1.69 mAh cm–2), the full cell retains 80% capacity after 1300 cycles at 1 C. This dual-gradient synergistic coupling ensures rapid Li+ transport across the entire electrode, fundamentally enabling a bottom-up Li-plating, significantly extending the cycle life of the 3D Li composite anode, and providing insights for future gradient design.

The significant power held by lithium metal (Li0) anodes has remained promising on paper for nearly a century owing to its extreme reactivity and the consequent severe interfacial instability. Here we report the effect of sequential interfacial electrochemistry in regulating the Li0-reactivity that convolutes Li+ transport, Li0 deposition, and solid-electrolyte interphase (SEI) formation. Combining experimental observations and theoretical calculations, we reveal that crystalline oxides coordinate interfacial cation-anion interactions and enforce structural and chemical orders at the Li0-electrolyte interface. The ordered microenvironment reorganizes the otherwise chaotic, multistep reactions into a temporally and spatially coherent sequence that orchestrates solvation regulation, Li0 nucleation and growth, and SEI assembly, thereby markedly enhancing the stability of the Li0 electrodes. The dual-regulation principle thus established exerts energetic and spatial control through sequenced interfacial chemistry that could offer a universal strategy for stabilizing reactive metal anodes across diverse battery chemistries.

In solid-state lithium-ion batteries, composite polymer-ceramic electrolytes (CPEs) of poly(ethylene oxide) (PEO) and nanosized Li6.4La3Zr1.4Ta0.6O12 (LLZTO) particles combine polymer-like flexibility and processability with significantly enhanced ionic conductivity and electrochemical stability from the ceramic filler, forming a promising electrolyte system. However, the poor interfacial compatibility between LLZTO and PEO leads to inhomogeneous filler distribution during electrolyte preparation, compromising both interfacial stability and discharge capacity in solid-state batteries. To address this, we developed an effective modification approach involving PEG-functionalized LLZTO through ultrasonic-assisted solution processing, followed by composite electrolyte fabrication with PEO. This method significantly improves LLZTO dispersion homogeneity within the polymer matrix. The optimized CPEs demonstrate superior electrochemical performance, including high ionic conductivity (∼1.0 × 10–4 S cm–1 at 25 °C), exceptional electrochemical stability (up to 5.24 V vs Li+/Li), and excellent interfacial compatibility with lithium metal anodes. Consequently, the assembled Li//CPE//LiFePO4 all-solid-state batteries deliver a high initial discharge capacity of 147.1 mAh g–1 and outstanding cycling stability with 99.0% capacity retention after 100 cycles at 0.5C (55 °C).

Short-term electricity price forecasting (STEP) plays a pivotal role in ensuring the stability and economic efficiency of modern power markets, especially under conditions of high volatility and increasing renewable penetration. However, existing models fail to adequately capture extreme price spikes, hierarchical periodic structures, and the dynamic impact of exogenous variables. To overcome these challenges, we propose Fourier-EPNet, a novel deep learning framework that integrates frequency-domain attention with multimodal variable fusion. Specifically, it features: (i) a Fourier Softmax attention mechanism, which extracts dominant periodic signals while suppressing high-frequency noise; and (ii) an exogenous-endogenous cross-attention module, which dynamically aligns historical price trends with forward-looking external drivers such as load and wind forecasts. Extensive experiments on five benchmark datasets (NP, PJM, BE, FR, DE) from the EPF corpus show that Fourier-EPNet consistently surpasses state-of-the-art baselines, achieving 49.5% lower MSE and 40.4% lower MAE on average. Ablation studies and theoretical visualization further validate the contribution and interpretability of each component. Overall, Fourier-EPNet offers a robust, interpretable, and generalizable solution for real-world electricity price forecasting, setting a strong foundation for intelligent energy market decision-making.