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Cobalt diselenide (CoSe2) has drawn great concern as an anode material for sodium-ion batteries due to its considerable theoretical capacity. Nevertheless, the poor cycling stability and rate performance still impede its practical implantation. Here, CoSe2/nitrogen-doped carbon-skeleton hybrid microcubes with a TiO2 layer (denoted as TNC-CoSe2) are favorably prepared via a facile template-engaged strategy, in which a TiO2-coated Prussian blue analogue of Co3[Co­(CN)6]2 is used as a new precursor accompanied with a selenization procedure. Such structures can concurrently boost ion and electron diffusion kinetics and inhibit the structural degradation during cycling through the close contact between the TiO2 layer and NC-CoSe2. Besides, this hybrid structure promotes the superior Na-ion intercalation pseudocapacitance due to the well-designed interfaces. The as-prepared TNC-CoSe2 microcubes exhibit a superior cycling capability (511 mA h g–1 at 0.2 A g–1 after 200 cycles) and long cycling life (456 mA h g–1 at 6.4 A g–1 for 6000 cycles with a retention of 92.7%). Coupled with a sodium vanadium fluorophosphate (Na3V2(PO4)2F3)@C cathode, this assembled full cell displays a specific capacity of 281 mA h g–1 at 0.2 A g–1 for 100 cycles. This work can be potentially used to improve other metal selenide-based anodes for rechargeable batteries.

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Na3V2(PO4)2F3 (NVPF) is a suitable cathode for sodium‐ion batteries owing to its stable structure. However, the large radius of Na+ restricts diffusion kinetics during charging and discharging. Thus, in this study, a phosphomolybdic acid (PMA)‐assisted hydrothermal method is proposed. In the hydrothermal process, the NVPF morphologies vary from bulk to cuboid with varying PMA contents. The optimal channel for accelerated Na+ transmission is obtained by cuboid NVPF. With nitrogen‐doping of carbon, the conductivity of NVPF is further enhanced. Combined with crystal growth engineering and surface modification, the optimal nitrogen‐doped carbon‐covered NVPF cuboid (c‐NVPF@NC) exhibits a high initial discharge capacity of 121 mAh g−1 at 0.2 C. Coupled with a commercial hard carbon (CHC) anode, the c‐NVPF@NC||CHC full battery delivers 118 mAh g−1 at 0.2 C, thereby achieving a high energy density of 450 Wh kg−1. Therefore, this work provides a novel strategy for boosting electrochemical performance by crystal growth engineering and surface modification.

Silicon is considered one of the most promising next-generation anode materials for lithium-ion batteries. It has the advantages of high theoretical specific capacity (4200 mAh·g–1), which is 10 times larger than that of a commercial graphite anode (372 mAh·g–1). However, there are some problems such as the pulverization of the electrode and an unstable solid electrolyte interphase (SEI) layer aroused by the huge bulk effect (>300%) of Si during the repeated lithiation/delithiation process. A binder plays a vital role in the conventional lithium-ion batteries that can effectively relieve the bulk expansion stress of a silicon anode. In this work, the inorganic cross-linker sodium borate (SB) and the commonly used binder sodium alginate (SA) were condensed through an esterification reaction and the reaction product was marked as SA–SB. It is found that the mechanical robustness and the peel strength of SA–SB are improved after cross-linking, which is conducive to maintaining the structural stability of the silicon anode in long cycle life. In consequence, the capacity retention of the silicon anode using the SA–SB binder (64.1%) is higher than that of SA (50.6%) after 100 cycles at 0.2 A·g–1.

Zinc metal anode, the most promising candidate material for rechargeable aqueous zinc‐ion batteries, has attracted considerable attention due to its abundant resources and low cost. However, hydrogen evolution reaction and uncontrollable zinc dendrite growth on zinc metal anode are the essential issues that strictly limit their practical application. Here, a modified Zn with a titanium nitride (TiN) protective layer (TiN@Zn) using a simple solvent casting approach is developed, which can simultaneously suppress the hydrogen evolution reaction and control the zinc dendrite growth when acting like a protective layer on the Zn anode. In situ  differential electrochemical mass spectrometry approach shows that the TiN coating layer can effectively suppress the hydrogen evolution. Additionally, the TiN can offer large Zn nucleation sites, narrowing the Zn nucleation energy barrier, leading to a uniform Zn deposition. Thus, in symmetric cells, the TiN@Zn electrode presents a stable Zn plating/striping (600 h at 1 mA cm−2) and lower potential hysteresis (38 mV), resulting in an improved electrochemical performance for TiN@Zn||MnO2 full cell.

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