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Self‐direction has become an important skill in the 21st century. To cultivate learners with a high level of self‐direction, it is necessary to diagnose their self‐directed learning (SDL) ability. This study diagnosed and predicted learners' SDL ability based on their actual SDL behaviours. The study was performed in a self‐directed 3D design class lasting 90 minutes. A total of 193 middle school students participated in the study. The results of the Pearson correlation analysis (p < 0.001) showed that the reported perception of SDL ability was significantly correlated with SDL behaviours. The results of the hierarchical multiple linear regression analysis showed that the SDL behaviours explained 84.9% of the variance in SDL ability (adjusted R2 = 0.849, p < 0.001). Therefore, SDL behaviours had significant predictive effects on the reported perception of SDL ability. Moreover, based on the random forest algorithm, the study built an SDL ability prediction model with high performance (accuracy = 0.83, precision = 0.82, recall = 0.84) using SDL behaviours as features. The study provides evidence for the design of effective strategies to enhance SDL ability and promote SDL behaviours.Practitioner notesWhat is already known about this topicTo cultivate learners with a high level of self‐direction, it is necessary to diagnose their self‐directed learning (SDL) ability.SDL is a combination of internal personal attributes and external autonomous behaviours.Few studies have focused on diagnosing SDL ability based on learners' external SDL behaviours occurring during the learning process.What this paper addsThe reported perception of SDL ability was significantly correlated with SDL behaviours.SDL behaviours had significant predictive effects on the reported perception of SDL ability.Based on the random forest algorithm, the study built an SDL ability prediction model with high performance using SDL behaviours as features.Implications for practice and/or policyThe findings indicate that instructors could design effective strategies to promote SDL behaviours for the purpose of enhancing learners' SDL ability.The method and process of building an SDL ability prediction model might provide a reference for related research on ability prediction with behaviours. [ABSTRACT FROM AUTHOR]

The Co‐free Ni‐rich layered cathode materials with excellent structural stability and low‐cost in Ni‐rich family are emerging as the promising candidates for the next generation of high‐energy density cathodes. Previously, Mn is generally regarded as the structural stabilizer in Co‐free Ni‐rich cathodes, while the role of inevitable Li/Ni intermixing is underestimated. Herein, the study reveals that the real origin of the lattice oxygen/structure stability of Co‐free Ni‐rich cathodes is dominated more by Li/Ni intermixing than the widely accepted Mn. In the Li/Ni intermixing configuration, the intermixed Ni ions can suppress the oxidation of lattice oxygen by increasing the formation energy of oxygen vacancy and reducing charge compensation. Besides, the Li vacancy formed via the delithiation of intermixed Li in transition metal layer can serve as O2 capture sites. This dual stabilization mechanism is proposed and proved to be effectively in enhancing the reversibility of lattice oxygen and the stability of material structural. This work sheds light on the mechanism of stabilizing lattice oxygen through Li/Ni intermixing, which provides new insights for designing better batteries. [ABSTRACT FROM AUTHOR]

LiFePO4 is one of the most widely used cathode materials for lithium‐ion batteries, and the low‐temperature performance of LiFePO4‐based batteries has been widely studied in recent years. Herein, a 3.5 Ah pouch‐type full battery was assembled using LiFePO4 as the cathode and artificial graphite as the anode. For the LiFePO4‐based cathode, carbon‐coated aluminum foil was selected as the current collector, and a 0D–1D–2D multi‐scale conductive network was introduced into the electrode. Notably, both the carbon‐coated current collector and novel conductive network could significantly reduce the internal resistance of the LiFePO4‐based battery, thus improving its electrochemical dynamics and low‐temperature performance. This paper provides a theoretical basis for the development of low‐temperature LiFePO4‐based batteries. [ABSTRACT FROM AUTHOR]

As an emerging post‐lithium battery technology, aluminum ion batteries (AIBs) have the advantages of large Al reserves and high safety, and have great potential to be applied to power grid energy storage. But current graphite cathode materials are limited in charge storage capacity due to the formation of stage‐4 graphite‐intercalated compounds (GICs) in the fully charged state. Herein, we propose a new type of cathode materials for AIBs, namely polycyclic aromatic hydrocarbons (PAHs), which resemble graphite in terms of the large conjugated π bond, but do not form GICs in the charge process. Quantum chemistry calculations show that PAHs can bind AlCl4− through the interaction between the conjugated π bond in the PAHs and AlCl4−, forming on‐plane interactions. The theoretical specific capacity of PAHs is negatively correlated with the number of benzene rings in the PAHs. Then, under the guidance of theoretical calculations, anthracene, a three‐ring PAH, was evaluated as a cathode material for AIBs. Electrochemical measurements show that anthracene has a high specific capacity of 157 mAh g−1 (at 100 mA g−1) and still maintains a specific capacity of 130 mAh g−1 after 800 cycles. This work provides a feasible "theory guides practice" research model for the development of energy storage materials, and also provides a new class of promising cathode materials for AIBs. [ABSTRACT FROM AUTHOR]

The rationally structural engineering is an efficient strategy to improve the comprehensive performance of potassium‐ion storage anode materials. In this paper, a hybrid with hollow FeS2 nanoparticles anchored into the 3D carbon skeleton (labeled as H‐FeS2@3DCS) is successfully constructed through two critical steps of in situ chemical deposition and anion‐exchange reaction strategies. In the former, the water‐soluble Na2CO3 crystals are used as hard templates for the preparation of 3DCS, while Fe3+‐containing aqueous solutions are utilized to remove the Na2CO3 templates. Interestingly, the intense collision between Fe3+ and CO32‐ in aqueous solution produces nanoscale Fe(OH)3 colloidal particles, which are firmly anchored into the pores of the carbon skeleton to form a "lotus‐seed"‐like nanostructure. In the latter case, a central void space is created inside the FeS2 nanoparticles due to the different diffusion rates of S‐anions and Fe‐cations during the subsequent sulfidation process. Thanks to this unique composition model, the H‐FeS2@3DCS hybrid not only alleviates the volume expansion efficiently by rationally hollow structure design, but also provides spacious "roads" (3D carbon skeleton) and "houses" (hollow FeS2 nanoparticles) for fast K‐ion transition and storage. As the anode of PIBs and PIHCs, the resultant H‐FeS2@3DCS electrode delivers an obviously enhanced K‐ions storage performance over state‐of‐the‐art. [ABSTRACT FROM AUTHOR]