A renewable-biomolecule-based electrode is developed through a facile synchronous reduction and self-assembly process, without any binder or additional conductive agent. The hybridized electrodes can be fabricated with arbitrary size and shape and exhibit superior capacity and cycle performance. The renewable-biomaterial-based high-performance electrodes will hold a place in future energy-storage devices.

Electrochemical water splitting requires efficient, low‐cost water oxidation catalysts to accelerate the sluggish kinetics of the water oxidation reaction. A rapid photocorrosion method is now used to synthesize the homogeneous amorphous nanocages of Cu‐Ni‐Fe hydr(oxy)oxide as a highly efficient electrocatalyst for the oxygen evolution reaction (OER). The as‐fabricated product exhibits a low overpotential of 224 mV on a glassy carbon electrode at 10 mA cm−2 (even lower down to 181 mV when supported on Ni foam) with a Tafel slope of 44 mV dec−1 for OER in an alkaline solution. The obtained catalyst shows an extraordinarily large mass activity of 1464.5 A g−1 at overpotential of 300 mV, which is the highest mass activity for OER. This synthetic strategy may open a brand new pathway to prepare copper‐based ternary amorphous nanocages for greatly enhanced oxygen evolution.

Hollow hierarchical CoO nanocube/reduced graphene oxide (COG) composite has been fabricated with the sacrificial-template method and the subsequent thermal treatment. Hollow/porous architectures supply high specific surface area and buffer the volume change during the lithium uptake/release processes, while rGO matrix ensures the system conductivity and further reinforces the structure. Serving as the anode material of lithium ion battery, COG demonstrates high lithium storage capacity, reaching 1170 mA h g–1 at a current density of 150 mA g–1, which is much higher than the capacity of rGO-free hollow CoO nanocubes. Ninety-four percent retention after 60 cycles further proves its stable cyclability. The combination of the advantages of the as-prepared befitting nanostructure and the rGO should be responsible for the durable rate behavior and the high capacity. Moreover, unfully reduced graphene oxide was achieved with the assistance of the multifunctional Na2S2O3, leading to more disorders and defects left in the composite and should also afford a positive influence on the lithium storage performance of the COG.

A renewable-biomolecule-based full lithium-ion battery is successfully fabricated for the first time. Naturally derivable emodin and humic acid based electrodes are used as cathode and anode, respectively. The as-assembled batteries exhibit superb specific capacity and substantial operating voltage capable of powering a wearable electronic watch, suggesting the great potential for practical applications with the significant merits of sustainability and biocompatibility.

Currently, exploring high‐volumetric‐capacity electrode materials that allow for reversible (de‐)insertion of large‐size K+ ions remains challenging. Tellurium (Te) is a promising alternative electrode for storage of K+ ions due to its high volumetric capacity, confirmed in lithium‐/sodium‐ion batteries, and the intrinsic good electronic conductivity. However, the charge storage capability and mechanism of Te in potassium‐ion batteries (KIBs) have not been unveiled until now. Here, a novel K–Te battery is constructed, and the K+‐ion storage mechanism of Te is revealed to be a two‐electron conversion‐type reaction of 2K + Te ↔ K2Te, resulting in a high theoretical volumetric capacity of 2619 mAh cm−3. Consequently, the rationally fabricated tellurium/porous carbon electrodes deliver an ultrahigh reversible volumetric capacity of 2493.13 mAh cm−3 at 0.5 C (based on Te), a high‐rate capacity of 783.13 mAh cm−3 at 15 C, and superior long‐term cycling stability for 1000 cycles at 5 C. This excellent electrochemical performance proves the feasibility of utilizing Te as a high‐volumetric‐capacity active material for storage of K+ ions and will advance the practical application of KIBs.