Cascaded Spatial Confinement Enables Simultaneous Ultrahigh Energy and Power Densities in Planar Micro-Supercapacitors.

Chen, Yu; Wang, Ying; Wu, Wenpeng; Zhao, Yuhan; Shi, Wanyi; Zhao, Yang; Jiang, Lan; Qu, Liangti · ACS Nano · 2026

basic_science · Level V

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Abstract

Planar microsupercapacitors (P-MSCs) with high power density and conformal configurations could provide on-chip power supply in the design of highly integrated electronics. However, achieving a breakthrough in overall energy within a finite footprint requires establishing an effective structure-performance relationship. Here, we present a cascaded spatial confinement strategy to construct a 3D interlocked P-MSC that couples force fields with charge transport/storage behavior, enabling ion-electron enrichment. Laser-etched pyramid microarrays on graphite current collectors create capillary forces that confine both electrode slurry and electrolyte to build a compact conduction network, while establishing a robust ion-electron interaction interface, significantly facilitating ion accessibility and kinetics. Using Zn//active carbon (AC) P-MSC as an example, the strategy boosts active material utilization by over 2-fold, and delivers an outstanding energy density of 117.5 mWh cm<sup>-3</sup> and a power density of 2382.0 mW cm<sup>-3</sup>, exceeding those reported for Zn//AC P-MSCs by several to tens of times, and surpassing nearly all existing Zn-based P-MSCs in areal performance. The approach demonstrates reliable universality across various P-MSC systems (eight types are verified). Integrated devices show notable advantages in powering miniaturized electronics and flexible displays, possessing a voltage output approximately 4.7 times that of a same-sized dry battery, and are also configured as emergency power chips to charge smartphones.