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The conversion of solar‐thermal (ST) power into electrical power along with its efficient storage represents a crucial and effective approach to address the energy crisis. The thermoelectric (TE) generator can absorb ST power and transform it into electrical energy, making it a highly viable technology to achieve photo‐thermal conversion (PTC). However, the practical application of the pristine TE generator devices on a larger scale is still facing several challenges. On the one hand, the pristine TE generator device has low inherent PTC efficiency, thereby leading to low power conversion. On the other hand, such solar‐thermoelectric (STE) conversion does not provide the functionality of electric energy storage. Herein, an effective strategy has been proposed that employs a CoAl2O4 PTC coating to decorate the pristine TE generator for developing the STE generator device with the remarkable STE performance and then coupling this device with a supercapacitor (SC) for effective storage power. In comparison to the pristine TE generator, the developed STE device exhibited considerable enhancement in both the open‐circuit voltage (Voc) and its maximum power density, displaying more than a 4‐ and 15‐fold improvement, respectively. In addition, the feasibility of coupling this solar‐driven STE generator device in series with a SC for ST conversion and storage was verified, and the working mechanism has been elucidated. This work presents a promising approach to effectively convert and store clean solar power into electrical energy, enabling practical applications of STE generator devices in conjunction with other electrochemical energy storage devices. [ABSTRACT FROM AUTHOR]

Graphite sulfate (H2SO4-GICs), as a key precursor for graphene oxide (GO) synthesis, is difficult to synthesize by spontaneously forming H2SO4-GICs due to its huge diffusion resistance. Therefore, it is still a crucial challenge for improving the reaction kinetics of graphite flakes to form H2SO4-GICs. In this work, we discover that the amount of H2O2 plays an important role in determining the formation of H2SO4-GICs in the intercalation process. The trace H2O2 can trigger more O* during the reaction process, leading to the lattice distortion and reducing the interlayer diffusion resistance of graphite, and it was found that reducing the volume ratio of H2O2 would promote the intercalation of H2SO4 into graphite and form the stage-I H2SO4-GICs. Exfoliation efficiency and oxidation degree were improved after oxidation reaction. We also confirm that this method works for the exfoliation of large graphite, demonstrating the high-efficiency energy supply by adding minimal stoichiometric H2O2. The pretreated GO by trace-H2O2 (PGO-100:1) exhibits a large interlayer spacing due to the complete exfoliation; after reduction as Na+ ion storage anode material, RPGO-100:1 displays a high rate performance as well as outstanding kinetic behavior, indicating that the increased interlayer space of graphite resulting from the deep oxidation benefits fast migration of Na+ ions toward a high capacity contribution and improved rate capability. [ABSTRACT FROM AUTHOR]

2D ion‐intercalated metal oxides are emerging promising new electrodes for supercapacitors because of their unique layered structure as well as distinctive electronic properties. To facilitate their application, fundamental study of the charge storage mechanism is required. Herein, it is demonstrated that the application of in situ Raman spectroscopy and electrochemical quartz crystal microbalance with dissipation monitoring (EQCM‐D), provides a sufficient basis to elucidate the charge storage mechanism in a typical 2D cation‐intercalated manganese oxide (Na0.55Mn2O4·1.5H2O, abbreviated as NMO) in neutral and alkaline aqueous electrolytes. The results reveal that in neutral Na2SO4 electrolytes, NMO mainly displays a surface‐controlled pseudocapacitive behavior in the low potential region (0–0.8 V), but when the potential is higher than 0.8 V, an intercalation pseudocapacitive behavior becomes dominant. By contrast, NMO shows a battery‐like behavior associated with OH− ions in alkaline NaOH electrolyte. This study verifies that the charge storage mechanism of NMO strongly depends on the type of electrolyte, and even in the same electrolyte, different charging behaviors are revealed in different potential ranges which should be carefully taken into account when optimizing the use of the electrode materials in practical energy‐storage devices. A molecular‐level understanding of the charging mechanisms for 2D cation‐intercalated manganese oxide, by using operando Raman spectroscopy and an electrochemical quartz crystal microbalance with dissipation monitoring. The results show the charge storage mechanism of Na0.55Mn2O4·1.5H2O strongly depends on the type of electrolyte, and even in the same electrolyte, different charging behaviors are revealed in different potential ranges. [ABSTRACT FROM AUTHOR]