Coherent manipulation of the lithium plating pattern is at the heart of the safe operation of metallic anodes in the battery technologies. In this article, a lightweight (~0.3 mg cm⁻²), dual-functionalized carbon spheres are anchored onto the Cu foil as the interfacial protective layer via the chelation process of the catechol groups in the polydopamine precursor and the copper foil. The dual-functionalized carbon spheres exhibit the intriguing complementary features: Lithiophilic nitrogen dopants favor the Li⁺ ion absorption and mitigate the nucleation barrier, while the micro/mesopore reservoir spatially homogenizes the ion flux distribution, confining the metallic propagation without dendrite-like protrusions. The metallic anode exhibits an ultra-stable plating/stripping process for 1400 hr with the average Coulombic efficiency of ~99%. A full-cell prototype is constructed by pairing the N-doped carbon spheres on the bare Cu (NCS-Cu) electrode with the high-mass-loading LiVPO₄F (12.5 mg cm⁻²) cathode that can deliver a high energy density of 421.2 Wh kg⁻¹ with the highest power density of 2106 W kg⁻¹ to promise the anode use for high-power/energy-dense metallic batteries.

The rational design of electrodes is the key to achieving ultrahigh-power performance in electrochemical energy storage devices. Recently, we have constructed well-organized and integrated three-dimensional (3D) carbon tube (CT) grids (3D-CTGs) using a 3D porous anodic aluminum oxide template-assisted method as electrodes of electrical double-layer capacitors (EDLCs), showing excellent frequency response performance. The unique design warrants fast ion migration channels, excellent electronic conductivity, and good structural stability. This study achieved one of the highest carbon-based ultrahigh-power EDLCs with the 3D-CTG electrodes, resulting in ultrahigh power of 437 and 1708 W·cm⁻³ with aqueous and organic electrolytes, respectively. Capacitors constructed with these electrodes would have important application prospects in the ultrahigh-power output. The rational design and fabrication of the 3D-CTGs electrodes have demonstrated their capability to build capacitors with ultrahigh-power performance and open up new possibilities for applications requiring high-power output.

Printed micro-supercapacitor exhibits its flexibility in geometry design and integration, showing unprecedented potential in powering the internet of things and portable devices. However, the printing process brings undesired processing defects (e.g., coffee ring effect), resulting in severe self-discharge of the printed micro-supercapacitors. The impact of such problems on device performance is poorly understood, limiting further development of micro-supercapacitors. Herein, by analyzing the self-discharge behavior of fully printed micro-supercapacitors, the severe self-discharge problem is accelerated by the ohmic leakage caused by the coffee ring effect on an ultrathin polymer electrolyte. Based on this understanding, the coffee ring effect was successfully eradicated by introducing graphene oxide in the polymer electrolyte, achieving a decline of 99% in the self-discharge rate. Moreover, the micro-supercapacitors with uniformly printed polymer electrolyte present 7.64 F cm^-3 volumetric capacitance (14.37 mF cm^-2 areal capacitance), exhibiting about 50% increase compared to the one without graphene oxide addition. This work provides a new insight to understand the relationship between processing defects and device performance, which will help improve the performance and promote the application of printed micro-supercapacitors.