The advancement of miniaturized electronic devices requires the development of high-performance microsupercapacitors. The low areal energy density of microsupercapacitors with the interdigitated architecture is the major challenge hindering the application. Here, a simple method for the scalable fabrication of all-solid-state, flexible microsupercapacitors is demonstrated by direct graphene-carbon nanotube composite ink writing technology. The microsupercapacitors demonstrate good electrochemical performance with a high areal energy density of 1.36 µWh cm -2 and power density of 0.25 mW cm -2 , good cycling stability, and excellent mechanical flexibility. The method developed here sheds light on the simple method of preparing high-performance, all-solid-state, flexible microsupercapacitors in a straightforward and scalable process.

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Exploring new battery technologies will promote the advance of energy storage systems. Designing a symmetrical‐structured rechargeable battery with the same electrode materials is a meaningful exploration for battery technology. Here, a solution‐processed all‐V2O5 rechargeable battery with V2O5 as both anode and cathode is presented, in which the anionic/cationic redox reactions are decoupled by precisely clamping its working potential windows. The battery shows good electrochemical performance with high capacity of 151 mAh g−1 at 0.10 C, good rate performance with 70% capacity retention when the current increases from 0.10 to 5 C, and promising cycling stability over 83% capacity retention after 900 cycles at 1 C. Moreover, the battery is highly profitable for simplified fabrication and scalable production, which benefits from its symmetrical configuration as well as the solution‐processed strategy. This work offers a new paradigm to construct advanced symmetrical energy storage devices.

The strain variation of LiNi 0.8 Co 0.1 Mn 0.1 O 2 (NCM) during cycling deteriorates its structural integrity and causes microcracks, resulting in a quick capacity decay. Enhancing NCM's structural integrity can suppress microcrack occurrence, thereby increasing its capacity retention. Here, we experimentally realize the microcrack suppression in NCM by enhancing its structural stability via the synchronous Li 2 SiO 3 coating. The Li 2 SiO 3 -coated NCM (NCM@LSO) is prepared by the precoating and solid-state lithiation methods. NCM@LSO exhibits good structural integrity with a high capacity retention of 97% after 500 cycles at 0.5 C, while NCM suffers serious microcracks with only 79% capacity retention after 450 cycles at 0.5 C. The microscopies and elemental analysis support that Li 2 SiO 3 coating not only stabilizes NCM's structural integrity by increasing its strain tolerance and avoiding microcrack occurrence but also affects the formation and distribution of a cathode electrolyte interphase on NCM. These effects result in the improved cycling stability of NCM@LSO. The work developed here sheds light on the development of high-performance NCM. KEYWORDS: LiNi 0.8 Co 0.1 Mn 0.1 O 2 , surface coating, mechanical strain, microcracks, structural integrity

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