Biomimetic Solid-State Zn²⁺ Electrolyte for Corrugated Structural Batteries

Abstract

Batteries based on divalent metals, such as the Zn/Zn2+ pair, represent attractive alternatives to lithium-ion chemistry due to their high safety, reliability, earth-abundance, and energy density. However, archetypal Zn batteries are bulky, inflexible, non-rechargeable, and contain a corrosive electrolyte. Suppression of the anodic growth of Zn dendrites is essential for resolution of these problems and requires materials with nanoscale mechanics sufficient to withstand mechanical deformation from stiff Zn dendrites. Such materials must also support rapid transport Zn2+ ions necessary for high Coulombic efficiency and energy density, which makes the structural design of such materials a difficult fundamental problem. Here, we show that it is possible to engineer a solid Zn2+ electrolyte as a composite of branched aramid nanofibers (BANFs) and poly­(ethylene oxide) by using the nanoscale organization of articular cartilage as a blueprint for its design. The high stiffness of the BANF network combined with the high ionic conductivity of soft poly­(ethylene oxide) enable effective suppression of dendrites and fast Zn2+ transport. The cartilage-inspired composite displays the ionic conductance 10× higher than the original polymer. The batteries constructed using the nanocomposite electrolyte are rechargeable and have Coulombic efficiency of 96–100% after 50–100 charge–discharge cycles. Furthermore, the biomimetic solid-state electrolyte enables the batteries to withstand not only elastic deformation during bending but also plastic deformation. This capability make them resilient to different type of damage and enables shape modification of the assembled battery to improve the ability of the battery stack to carry a structural load. The corrugated batteries can be integrated into body elements of unmanned aerial vehicles as auxiliary charge-storage devices. This functionality was demonstrated by replacing the covers of several small drones with corrugated Zn/BANF/MnO2 cells, resulting in the extension of the total flight time. These findings open a pathway to the design and utilization of corrugated structural batteries in the future transportation industry and other fields of use.

Do Zinc Dendrites Exist in Neutral Zinc Batteries: A Developed Electrohealing Strategy to In Situ Rescue In‐Service Batteries

“…On the one hand, some researchers believe the limited lifespan of ZBs suffers severely from the dendritic issues even in neutral electrolytes . At this aspect, strategies focusing on liquid electrolyte modification, interface protecting layer, and solid‐state electrolyte were successively developed and prolonged the lifespan to ≥1000 cycles together with large capacity retention up to 90% (as listed in Table 1, Supporting Information) . On the other hand, others claim that Zn plating/stripping can stably proceeds in a nondendrite manner.…”

Recent Advances in Polymer Electrolytes for Zinc Ion Batteries: Mechanisms, Properties, and Perspectives

“…Due to the high mechanical durability, the flexible battery could operate placidly in some complicated conditions, as indicated in Figure 13e. Wang et al171 constructed a HPE containing the branched aramid nanofibers (BANFs), PEO, and Zn(CF 3 SO 3 ) 2 . A fibrous 3D network in BANFs could provide nanoscale pores for ion transport and suppress zinc dendrite growth.…”

“…Taken together, electrode with high active surface area is vital for a stable SEI, which can give impressive cyclability. However, when the bulk of the anode is enlarged, the mechanical damage is subject to be presented 171. Therefore, there are still several fundamental issues to be solved.…”

Nature-inspired electrocatalysts and devices for energy conversion

“…Finally, the calcified zone secures the cartilage to the bone by attaching the collagen fibrils of the deep zone to subchondral bone. 394 To imitate the nanofiber networks of cartilage, aramid nanofibers were synthesized from Kevlar via layer-by-layer deposition and used as ion conducting membranes for Li-ion batteries, 396 solid electrolytes for Zn batteries, 397 and separators for redox flow batteries. 398 Ion conducting membranes are a key component of Li-ion batteries, providing high ionic mobility to Li + ions, stiffness and flexibility.…”

“…Solid electrolytes can provide a solution to this issue at the expense of low mobility of divalent ions, leading to low energy density. 397 A cartilage-inspired composite of aramid nanofibers, poly-ethylene oxide (PEO) and zinc trifluoromethanesulfonate (Zn(CF 3 SO 3 ) 2 ) can serve as a solid electrolyte providing facile ion transport and excellent mechanical properties. 397 PEO and Zn(CF 3 SO 3 ) 2 act as the ion transport components of the solid electrolyte; the composition of PEO/Zn(CF 3 SO 3 ) 2 /aramid nanofibers was optimized with respect to Zn 2+ conductivity and mechanical properties with an optimal ratio of 9 : 3 : 1.…”