No abstract

1,2-Dimethoxyethane (DME) is a common electrolyte solvent for lithium metal batteries. Various DME-based electrolyte designs have improved long-term cyclability of high-voltage full cells. However, insufficient Coulombic efficiency at the Li anode and poor high-voltage stability remain a challenge for DME electrolytes. Here, we report a molecular design principle that utilizes a steric hindrance effect to tune the solvation structures of Li+ ions. We hypothesized that by substituting the methoxy groups on DME with larger-sized ethoxy groups, the resulting 1,2-diethoxyethane (DEE) should have a weaker solvation ability and consequently more anion-rich inner solvation shells, both of which enhance interfacial stability at the cathode and anode. Experimental and computational evidence indicates such steric-effect-based design leads to an appreciable improvement in electrochemical stability of lithium bis­(fluoro­sulfonyl)­imide (LiFSI)/DEE electrolytes. Under stringent full-cell conditions of 4.8 mAh cm–2 NMC811, 50 μm thin Li, and high cutoff voltage at 4.4 V, 4 M LiFSI/DEE enabled 182 cycles until 80% capacity retention while 4 M LiFSI/DME only achieved 94 cycles. This work points out a promising path toward the molecular design of non-fluorinated ether-based electrolyte solvents for practical high-voltage Li metal batteries.

Deformable energy storage devices are needed to power the next generation of wearable electronics. This review highlights the most recent advances in stretchable energy storage devices with a focus on batteries and supercapacitors.

No abstract

Due to their high water content and macroscopic connectivity, hydrogels made from the conducting polymer PEDOT:PSS are a promising platform from which to fabricate a wide range of porous conductive materials that are increasingly of interest in applications as varied as bioelectronics, regenerative medicine, and energy storage. Despite the promising properties of PEDOT:PSS‐based porous materials, the ability to pattern PEDOT:PSS hydrogels is still required to enable their integration with multifunctional and multichannel electronic devices. In this work, a novel electrochemical gelation (“electrogelation”) method is presented for rapidly patterning PEDOT:PSS hydrogels on any conductive template, including curved and 3D surfaces. High spatial resolution is achieved through use of a sacrificial metal layer to generate the hydrogel pattern, thereby enabling high‐performance conducting hydrogels and aerogels with desirable material properties to be introduced into increasingly complex device architectures.

No abstract

The commercialization of rechargeable lithium-ion batteries (LIBs) has revolutionized the modern lifestyle, [1] leading society into an electrified, wireless, and sustainable future. With the continuous upsurge in demand for energy-dense devices, future advancement of batteries will require higher energy density, longer cycle life, and better safety. [2,3] Lithium metal anodes have a high specific capacity of ≈3800 mAh g −1 , [4,5] enabling the possibility of higher energy density batteries. However, commonly used liquid electrolytes in Li metal batteries (LMBs) often result in uncontrollable lithium dendrite growth, inadequate electrochemical and thermal stability, and high flammability. [2,4] As a result, limited performance and safety issues restrict the application and development of LMBs based on conventional liquid electrolytes.Compared to liquid electrolytes, solidstate electrolytes (SSEs) can potentially provide better safety, higher mechanical strength, and excellent chemical and electrochemical stability. [4,[6][7][8][9][10] SSEs can be grouped into three categories: inorganic solid electrolytes, [11][12][13][14] solid polymer electrolytes (SPEs), [15][16][17] and their hybrids. [18][19][20][21] Among them, inorganic solid electrolytes have the highest ionic conductivity [11] and excellent thermal stability, [2] but their interfacial compatibility, brittleness, and rigidity [22,23] are the challenges to be addressed towards their practical application. [9] In contrast, SPEs have good interfacial compatibility, [24] and excellent chemical and electrochemical stability, [18,24,25] but are lacking in thermal stability and mechanical strength, which generally makes them insufficient for meeting the requirements of high-safety and high-performance LMBs, [6,26,27] especially at high temperatures (>100 °C). [28] A hybrid of ceramic and polymer SSEs may offer good mechanical strength and safety, but it is still challenging to achieve ultrathin composite SSEs. Therefore, the design of a robust, ultrathin SSE that fulfills the above requirements is urgently needed.To achieve an energy density comparable to or larger than liquid electrolyte-based cells, ultrathin and lightweight solid electrolytes are necessary. [29,30] Compared to typical, thick ceramic electrolytes with thicknesses in the range of a few hundred microns, [14,[31][32][33] SPEs and their composites are easily engineered and manufacturable for tunable smaller All-solid-state batteries (ASSBs) demonstrate great promise, offering high energy density, good thermal stability, and safe operation compared with traditional Li-ion batteries. Among various solid-state electrolytes (SSEs), solid polymer electrolytes (SPEs) offer an attractive choice due to their thinness, low density, and good manufacturability. However, ultrathin SPEs that work with practical current densities or at high temperatures remain challenging, limiting applicable conditions of SPE-based batteries. Here, the authors report a novel scalable, ultrathin, and high-temperature-resistant ...

A fundamental challenge, shared across many energy storage devices, is the complexity of electrochemistry at the electrode–electrolyte interfaces that impacts the Coulombic efficiency, operational rate capability, and lifetime. Specifically, in energy-dense lithium metal batteries, the charging/discharging process results in structural heterogeneities of the metal anode, leading to battery failure by short-circuit and capacity fade. In this work, we take advantage of organic cations with lower reduction potential than lithium to build an electrically responsive polymer interface that not only adapts to morphological perturbations during electrodeposition and stripping but also modulates the lithium ion migration pathways to eliminate surface roughening. We find that this concept can enable prolonging the long-term cycling of a high-voltage lithium metal battery by at least twofold compared to bare lithium metal.