I‐containing Polymer/Alloy Layer‐Based Li Anode Mediating High‐Performance Lithium–Air Batteries

Abstract

Lithium (Li)–air batteries with super‐high energy density have attracted wide attention, but they usually exhibit poor performance due to dendrite/passivation on anode and insoluble discharge products on cathode. Many recent works have just designed highly efficient catalysts or only prepared stable anodes to solve one aspect of the above issues. Herein, an iodine (I)‐containing polymer/alloy layer‐based Li (IPA‐Li) via the replacement reaction of zinc iodide (ZnI2) and Li and subsequent polymerization of ethyl α‐cyanoacrylate (ECA) is designed to tackle both the anode and cathode problems. The homogeneous polymer layer and LiZn alloy in IPA‐Li not only suppress the passivation caused by attack of O2/H2O, but also guide uniform Li plating/stripping behavior to inhibit dendrite formation. Moreover, soluble I‐containing species in IPA‐Li obviously promote decomposition of discharge products at low voltages. Compared with bare Li, IPA‐Li shows a longer lifespan (1200 h at 1 mA cm−2) in the symmetric cell. Hence, the electrochemical performance of IPA‐Li‐based Li–O2 batteries is also much better than Li‐based cells. Moreover, IPA‐Li‐based Li–air battery operates stably >120 cycles with low‐overpotential of <1.6 V in ambient air, while the Li–air battery fast decays only after 25 cycles. This strategy provides a new way to construct high‐performance Li–air batteries.

Recent advances in solid‐state metal–air batteries

“…Li metal has a high theoretical energy density of 3860 mAh g −1 and low potential (−0.304 V vs. standard hydrogen electrode (SHE)), which is an ideal anode material. The interface physical/chemical compatibility between Li metal anode and solid electrolyte is still the subject of current research 38–41 . In previous studies, to reduce the interface resistance between Li metal anode and electrolyte, a small amount of liquid electrolyte is usually added (Figure 3A).…”

Nanostructure Engineering Strategies of Cathode Materials for Room-Temperature Na–S Batteries

“…Lithium-ion batteries (LIBs), which have relatively higher energy densities than those of other conventional electrochemical energy storage systems, have been widely employed in a great variety of fields such as mobile phones, electric watches, laptops, and even electric vehicles. − In the past decades, however, the state-of-the-art LIBs have been facing two key obstacles (i.e., expensive price and limited energy densities), which hinder their further development and scaled applications. For the former, the scarcity of Li resources substantially results in high cost of electrode materials, whereas their ever-increasing use, in turn, exacerbates the increase in the commercial price of electrode materials. − As for the latter, the ceiling of energy density of current LIBs is about 300 W h kg –1 , which is difficult to meet the urgent demand of long-served lifespan and long-distance electric transportation. , In terms of energy density, lithium–air (Li–air) batteries have aroused intense research interest because of their ultrahigh theoretical energy density (500 W h kg –1 ) and the easy availability of active materials in cathodes, which is 5–10 times higher than that of conventional LIBs. − However, many challenges are hindering development of Li–air batteries before competing with current dominate rechargeable LIBs, such as decomposition of carbon cathodes and electrolytes during cycling, the formation of Li 2 CO 3 and other Li carboxylates, and a large consumption of Li resources. These problems pose not only severe capacity fading and high cost but also safety concerns of Li–air batteries.…”

Molecular Langmuir–Blodgett Film for Silicon Anode Interface Engineering

“…Rechargeable batteries are pivotal for realizing vehicle electrification and large-scale green energy storage. − Despite the ubiquitous application of lithium-ion batteries (LIBs) in daily digital devices and in electric cars, the limited energy densities of contemporary LIBs pose outstanding obstacles for future evolution of battery-based portable electricity storage devices. − Consequently, substantial research efforts have been devoted to development of novel battery systems such as lithium–air batteries and lithium–sulfur batteries. − On the other hand, LIB is still an important player in the battery competition when silicon (Si) is employed, which is a low-cost anode material with a theoretically high capacity beyond 3500 mAh/g that is plausibly 10 times higher than that of graphite anodes. , Although principally favorable, Si anodes are confronted with a series of setbacks such as dramatic volume changes, high surface reactivity, and unstable solid electrolyte interphase (SEI) in charging and discharging processes. , Chemical developments of silicon anodes include binder engineering, , electrolyte optimization, − Si composite enhancement, − nanostructured Si anode, , and prelithiation. , It is also a common strategy to improve the SEI layers to minimize the adverse effects of Si lithiation/delithiation by electrolyte additives, which could electrochemically produce protective layers on electrode surfaces. − Additionally, functional artificial SEIs have been constructed with nonreactive thin films that are fabricated externally . For example, graphene-based artificial SEIs have been applied to the LiMn 2 O 4 cathode and the lithium metal anode to improve the performances of these electrodes.…”