The energy density of batteries can be increased by using high-load cathode material matched with sodium (Na) metal anode. However, the large polarization of the battery under such harsh conditions will promote the growth of Na dendrites and side reactions. Carbon materials are regarded as ideal modify layers on Na metal anode to regulate the Na⁺ plating/stripping behavior and inhibit the Na dendrites and side reactions due to their light weight, high stability and structural adjustability. However, commonly used carbon nanotubes and carbon nanofibers cannot enable these modified Na metal anodes to operate stably in full batteries with a high-load cathode (> 15 mg·cm⁻²). The most fundamental reason is that abundant polar functional groups on the surface bring serious side reactions and agglomerations lead to uneven Na⁺ flow. Here, a proof-of-concept study lies on fabrications of carbon nanospheres with small amount of polar functional groups and sodiophobic components on the surface of Na metal anode, which significantly enhances the uniformity of the Na⁺ plating/stripping. The assembled symmetric battery can cycle stability for 1300 h at 3 mA·cm⁻²/3 mAh·cm⁻². The full battery with high-load Na₃V₂(PO₄)₃ (30 mg·cm⁻²) maintains a Coulombic efficiency of 99.7% after 100 cycles.

Owing to their high volumetric capacity, low cost and high safety, rechargeable aluminum batteries have become promising candidates for energy applications. However, the high charge density of Al³⁺ leads to strong coulombic interactions between anions and the cathode, resulting in sluggish diffusion kinetics and irreversible collapse of the cathode structure. Furthermore, AlCl₃-based ionic liquids, which are commonly used as electrolytes in such batteries, corrode battery components and are prone to side reactions. The above problems lead to low capacity and poor cycling stability. Herein, we propose a reduced graphene oxide (rGO) cathode with a three-dimensional porous structure prepared using a simple and scalable method. The lamellar edges and oxygen-containing group defects of rGO synergistically provide abundant ion storage sites and enhance ion transfer kinetics. We matched the prepared rGO cathode with noncorrosive electrolyte 0.5 mol·L⁻¹ Al(OTF)₃/[BMIM]OTF and Al metal to construct a high-performance battery, Al||rGO-150, with good cycling stability for 2700 cycles. Quasi-in-situ physicochemical characterization results show that the ion storage mechanism is codominated by diffusion and capacitance. The capacity consists of the insertion of Al-based species cations as well as synergistic adsorption of Al(OTF)_x^(3−x)+ (x < 3) and [BMIM]⁺. The present study promotes the fundamental and applied research on rechargeable aluminum batteries.

Sodium-ion batteries are considered as a promising low-cost alternative to commercial lithium-ion batteries. However, the harsh preparation conditions and unsatisfactory electrochemical performance of most sodium-ion batteries anode materials limit their commercial applications. Herein, we develop a new alloying/dealloying method for producing nano-scale tin from freezing point to room temperature. Due to the unique surface properties of tin particles, a tin/carbon composite with a compact structure is obtained. When coupled with a diglyme-based electrolyte, tin/carbon composite (contains 60 wt.% tin) exhibits a reversible capacity of 334.8 mAh·g⁻¹ after 1,000 cycles at 500 mA·g⁻¹. An as-prepared tin/carbon anode||high-load vanadium phosphate sodium full cell (N/P ratio: 1.07) shows a stable cycle life of 300 cycles at 1 A·g⁻¹. The achievement of such an excellent performance can be ascribed to the carbon conductive network and robust solid electrolyte interphase film, which facilitates the fast transportation of electrons and Na ions. This work provides a new idea to prepare other alloyed anode materials for high-performance sodium-ion batteries.