The uncontrollable dendrite growth, hydrogen evolution, and other side‐reactions, originating from the zinc anode, have severely restricted the practical application of aqueous zinc–ion batteries (ZIBs). To address these challenges, a stable solid‐electrolyte‐interface (SEI) layer is constructed through introducing sericin molecules as an electrolyte additive to modulate the Zn nucleation and overpotential of hydrogen evolution. This SEI layer increases the nucleation overpotential during Zn plating, leading to the finer‐grained, dense, and uniform Zn deposition. Meanwhile, the lower unoccupied molecular orbital molecules in SEI layer have a higher reduction potential than H2O, inhibiting hydrogen production, and subsequently suppressing the Zn dendritic and interfacial side‐reactions. Consequently, the Zn|Zn symmetric cells with sericin additives exhibit an extremely prolonged cycling lifetime of 4446 h compared with to bare Zn electrode of 53 h at 1.0 mA cm−2/1.0 mAh cm−2, and a high average Coulombic efficiency of 99.29% under a high cumulative plated capacity of 1.0 Ah cm−2 tested in Zn|Cu cells. Moreover, the assembled full cells using Na2V6O16·3H2O cathodes endure 2000 cycles with high capacity retention of 81.7% at 5.0 A g−1. This study sheds new light on modulating the process of Zn nucleation and overpotential of H2 evolution for durable Zn anode design.

Flexible lithium-ion batteries (FLBs) are of critical importance to the seamless power supply of flexible and wearable electronic devices. However, the simultaneous acquirements of mechanical deformability and high energy density remain a major challenge for FLBs. Through billions of years of evolutions, many plants and animals have developed unique compositional and structural characteristics, which enable them to have both high mechanical deformability and robustness to cope with the complex and stressful environment. Inspired by nature, many new materials and designs emerge recently to achieve mechanically flexible and high storage capacity of lithiumion batteries at the same time. Here, we summarize these novel FLBs inspired by natural and biological materials and designs. We first give a brief introduction to the fundamentals and challenges of FLBs. Then, we highlight the latest achievements based on nature inspiration, including fiber-shaped FLBs, origami and kirigami-derived FLBs, and the nature-inspired structural designs in FLBs. Finally, we discuss the current status, remaining challenges, and future opportunities for the development of FLBs. This concise yet focused review highlights current inspirations in FLBs and wishes to broaden our view of FLB materials and designs, which can be directly "borrowed" from nature.

is due to their high specific energy density, long cycling lifespan, and portability. [7][8][9][10] Currently, state-of-the-art LIBs (without packaging materials) can achieve a high specific energy density of ≈250 Wh kg −1 . Next-generation LiS and Li-air systems can further increase the battery energy densities beyond 600 and 900 Wh kg −1 , respectively. [11,12] With the energy density increasing, more attention should be paid to the safety of LIBs, as the chemical energy can be abruptly released in the forms of fires and explosions once the battery is not properly handled. [13][14][15][16][17][18] Currently, the safety issues are also regarded as one of the significant challenging barriers that limit the widespread adoption of LIBs for modern electrical vehicles. [19,20] A typical lithium-ion cell is composed of an anode, a cathode, liquid electrolytes, and a separator, [1] as illustrated in Figure 1A. The active materials are mixed with polymer binders and conductive carbon additives and then coated onto aluminum and copper foil current collectors to make the cathode and anode, respectively. Layered, spinel, and polyanion-type lithium-transitional metal oxides and phosphates including LiCoO 2 , LiMn 2 O 4 , LiFePO 4 , and their derivatives (LiMn x Ni y O 4 , LiNi 1−y−z Mn y Co z O 2 , etc.) have been used as cathode materials for LIBs due to their high lithium intercalation capacity and potential. [5] Graphite is the most frequently used anode material for LIBs because of its high abundance, low cost, and good reversibility. [21,22] Other materials such as carbon, [23] silicon, [24][25][26] and transition metal oxides-based materials with various structures and compositions have been studied as anodes for LIBs. [27][28][29] Some of them show promising capacity but there are still many challenges in scaled-up productions and practical applications. [30,31] For details of studies on structural design and performance optimization of the LIB anode materials, readers may refer to a comprehensive review published recently. [32] The liquid electrolyte provides a medium for fast Li + ions transport. [33,34] The separator is applied to prevent direct contact between the cathode and anode while permitting the ion transfer. [35][36][37][38] During the charging process, Li + ions are deintercalated from the cathode host and insert into the anode. On discharge, Li + ions migrate reversely from the above process, and electrons pass through the external circuit, supplying electricity [1] (Figure 1A). A passivation layer of solid-electrolyte-interphase (SEI) is generated on the anode surface during the initial few charging cycles, As one of the most efficient electrochemical energy storage devices, the energy density of lithium-ion batteries (LIBs) has been extensively improved in the past several decades. However, with increased energy density, the safety risk of LIBs becomes higher too. The frequently occurred battery accidents worldwide remind us that safeness is a crucial requirement for LIBs, especially in environments ...

Potassium-ion batteries (PIBs) are a favorable alternative to lithium-ion batteries (LIBs) for the large-scale electrochemical storage devices because of the high natural abundance of potassium resources. However, conventional PIB electrodes usually exhibit low actual capacities and poor cyclic stability due to the large radius of potassium ions (1.39 Å). In addition, the high reactivity of potassium metal raises serious safety concerns. These characteristics seriously inhibit the practical use of PIB electrodes. Here, zinc phosphide composites are rationally designed as PIB anodes for operation in a nonflammable triethyl phosphate (TEP) electrolyte to solve the above-mentioned issues. The optimized zinc phosphide composite with 20 wt% zinc phosphate presents a high specific capacity (571.1 mA h g −1 at 0.1 A g −1 ) and excellent cycling performance (484.9 mA h g −1 with the capacity retention of 94.5% after 1000 cycles at 0.5 A g −1 ) in the KFSI-TEP electrolyte. XPS depth profile analysis shows that the improved cycling stability of the composite is closely related to the reversible dynamic evolutions and conversions of the sulfurcontaining species in the solid electrolyte interphase (SEI) during the charge/ discharge process. This dynamic reversible SEI concept may provide a new strategy for the design of superior electrodes for PIBs.

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