Lithium-oxygen batteries with ultrahigh energy density have received considerable attention as of the future energy storage technologies. The development of effective electrocatalysts and a ...corresponding working mechanism during cycling are critically important for lithium-oxygen batteries. Here, a single cobalt atom electrocatalyst is synthesized for lithium-oxygen batteries by a polymer encapsulation strategy. The isolated moieties of single atom catalysts can effectively regulate the distribution of active sites to form micrometre-sized flower-like lithium peroxide and promote the decomposition of lithium peroxide by a one-electron pathway. The battery with single cobalt atoms can operate with high round-trip efficiency (86.2%) and long-term stability (218 days), which is superior to a commercial 5 wt% platinum/carbon catalyst. We reveal that the synergy between a single atom and the support endows the catalyst with excellent stability and durability. The promising results provide insights into the design of highly efficient catalysts for lithium-oxygen batteries and greatly expand the scope of future investigation.
A photoinduced flexible Li‐CO2 battery with well‐designed, hierarchical porous, and free‐standing In2S3@CNT/SS (ICS) as a bifunctional photoelectrode to accelerate both the CO2 reduction and ...evolution reactions (CDRR and CDER) is presented. The photoinduced Li‐CO2 battery achieved a record‐high discharge voltage of 3.14 V, surpassing the thermodynamic limit of 2.80 V, and an ultra‐low charge voltage of 3.20 V, achieving a round trip efficiency of 98.1 %, which is the highest value ever reported (<80 %) so far. These excellent properties can be ascribed to the hierarchical porous and free‐standing structure of ICS, as well as the key role of photogenerated electrons and holes during discharging and charging processes. A mechanism is proposed for pre‐activating CO2 by reducing In3+ to In+ under light illumination. The mechanism of the bifunctional light‐assisted process provides insight into photoinduced Li‐CO2 batteries and contributes to resolving the major setbacks of the system.
Battery life on Mars: A photoinduced flexible Li‐CO2 battery with hierarchical, porous, and free‐standing In2S3@CNT/SS as a bifunctional photoelectrode to accelerate both CO2 reduction and evolution is presented. The Li‐CO2 battery achieved a record‐high discharge voltage of 3.14 V (thermodynamic limit: 2.80 V), and an ultra‐low charge voltage of 3.20 V, and a roundtrip efficiency of 98.1 %.
Photoassisted electrochemical reaction is regarded as an effective approach to reduce the overpotential of lithium–oxygen (Li–O2) batteries. However, the achievement of both broadband absorption and ...long term battery cycling stability are still a formidable challenge. Herein, an oxygen vacancy‐mediated fast kinetics for a photoassisted Li–O2 system is developed with a silver/bismuth molybdate (Ag/Bi2MoO6) hybrid cathode. The cathode can offer both double advantages for light absorption covering UV to visible region and excellent electrochemical activity for O2. Upon discharging, the photoexcited electrons from Ag nanoplate based on the localized surface plasmon resonance (LSPR) are injected into the oxygen vacancy in Bi2MoO6. The fast oxygen reaction kinetics generate the amorphous Li2O2, and the discharge plateau is improved to 3.05 V. Upon charging, the photoexcited holes are capable to decompose amorphous Li2O2 promptly, yielding a very low charge plateau of 3.25 V. A first cycle round‐trip efficiency is 93.8% and retention of 70% over 500 h, which is the longest cycle life ever reported in photoassisted Li–O2 batteries. This work offers a general and reliable strategy for boosting the electrochemical kinetics by tailoring the crystalline of Li2O2 with wide‐band light.
A facile oxygen vacancy‐mediated fast kinetics for an ultrawide band photoassisted Li–O2 system is developed. The bifunctional Ag/Bi2MoO6 cathode is favorable to promoting the oxygen reduction reaction and oxygen evolution reaction kinetics due to the discharge products is amorphous Li2O2. The reaction mechanism is revealed by in situ X‐ray diffraction and Raman spectroscopy.
Single atoms catalysts’ (SACs) applications in the energy storage field are hindered by their insufficient stability and poor recyclability due to their oxidation and agglomeration. To address this ...challenge, herein, a Co‐CMS composite material is synthesized by confining Co SACs into the highly ordered pores of the carbon molecular sieve (CMS). Related theoretical and experimental methods prove that the microporous trapping and hydroxyl doping of CMS are favorable for synergistically stabilizing the precursor and contributing to the subsequent conversion of single atoms with strong interactions between Co, O, and N. The unique 3D spiral pore structure of CMS facilitates the mass transfer of reactants and the highly dispersed Co single atoms confined in CMS increase the active sites. These properties are ideal for oxygen reduction reaction catalysts. Benefiting from the above‐mentioned superiority, the Co‐CMS cathode exhibits superior performance in a rechargeable Zn–air battery with a lower charge–discharge voltage gap of 0.77 V and a power density of 219 mW cm−2. The applications of Co‐CMS catalysts are also extended to other metal–air batteries in this work, which further highlights the advantages of carbon molecular sieves in stabilizing SACs materials.
A new strategy for using the confinement effect of hierarchical carbon molecular sieves (CMS) to stabilize single atoms is deeply studied. This strategy enables the fabrication of a satisfactory oxygen reduction reaction catalyst. The synergistic effect of the micropore capture effect and the hydroxyl group of CMS produce excellent results. The Co‐CMS catalyst displays promising applications in the field of metal–air batteries.
The photoassisted lithium–oxygen (Li–O2) system has emerged as an important direction for future development by effectively reducing the large overpotential in Li–O2 batteries. However, the ...advancement is greatly hindered by the rapidly recombined photoexcited electrons and holes upon the discharging and charging processes. Herein, a breakthrough is made in overcoming these challenges by developing a new magnetic and optical field multi‐assisted Li–O2 battery with 3D porous NiO nanosheets on the Ni foam (NiO/FNi) as a photoelectrode. Under illumination, the photogenerated electrons and holes of the NiO/FNi photoelectrode play a key role in reducing the overpotential during discharging and charging, respectively. By introducing the external magnetic field, the Lorentz force acts oppositely on the photogenerated electrons and holes, thereby suppressing the recombination of charge carriers. The magnetic and optical field multi‐assisted Li–O2 battery achieves an ultralow charge potential of 2.73 V, a high energy efficiency of 96.7%, and good cycling stability. This external magnetic and optical field multi‐assisted technology paves a new way of developing high‐performance Li–O2 batteries and other energy storage systems.
A renewable magnetic and optical field multi‐assisted Li–O2 battery is developed with porous NiO on the Ni foam as a photoelectrode. The battery achieves an ultralow charge potential of 2.73 V, a high energy efficiency of 96.7%, and good cycling stability. The effect mechanism of the improved battery performance with magnetic field and optical field is revealed.
Directly converting and storing abundant solar energy in next‐generation energy storage devices is of central importance to build a sustainable society. Herein, a new prototype of a light‐promoted ...rechargeable and flexible Li‐CO2 battery with a TiO2/carbon cloth (CC) cathode is reported for the direct utilization of solar energy to promote the kinetics of the carbon dioxide reduction reaction and carbon dioxide evolution reaction (CO2ER). Under illumination, photoelectrons are generated in the conduction band of TiO2/CC, followed by the enhancing diffusion of electrons and lithium ions during the discharge process. The photoelectrons on the cathode surface can regulate the morphology of the discharge product Li2CO3, contributing to boosting the kinetics of the subsequent CO2ER process. In the reverse charge process, photogenerated holes can favor the decomposition of Li2CO3, leading to a negative charge potential of 2.88 V without increased polarization over ≈60 h of cycling. Owing to an ultralow overpotential of 0.06 V between the discharge and charge process, an ultrahigh energy efficiency of 97.9% is attained under illumination. The introduction of a light‐promoted flexible Li‐CO2 battery can pave the way toward developing the use of solar energy to address the charging overpotential of conventional Li‐CO2 batteries.
A renewable light‐promoted flexible Li‐CO2 battery is developed inspired by the photoenergy conversion and utilization concept. The utilization of solar light can effectively alleviate the charge polarization and promote the Li+ diffusion and mass transfer, resulting in considerable improvement of the kinetics of the carbon dioxide reduction reaction and carbon dioxide evolution reaction processes in the Li‐CO2 battery.
The rechargeable zinc‐ion battery is regarded as a promising candidate for the next‐generation energy storage system, however, zinc dendrite growth and hydrogen evolution reaction (HER) have greatly ...hindered the practical application of the battery. Herein, a functionalized, nano‐engineering Zn2+ coordinated carboxylate cellulose solid‐state electrolyte (denoted as Zn‐CCNF@XG) for zinc‐ion battery is constructed through a straightforward approach. According to the experimental and density functional theory (DFT) results of dissociation energy, the notably decreased dissociation energy by −COOH is favorable to Zn2+ de‐coordinating and rapid ion‐hopping in Zn‐CCNF@XG to achieve high ionic conductivity and transference number. More importantly, the engineered molecular channels are beneficial to enlarging the distance between the nanofibril chains, providing a larger space for the movement of Zn2+. Benefiting from the coordination of Zn2+ with −OH in carboxylate cellulose nanofibrils, Zn‐CCNF@XG as a good ionic conductor displays a high ionic conductivity of 1.17 × 10−4 S cm−1 and transference number of 0.78. The Zn||NaV3O8·1.5H2O full cell with Zn‐CCNF@XG maintains a capacity retention of 83.46% with a coulombic efficiency of 99.99% after 3000 cycles (1 A g−1). The proposed strategy by introducing a functional group to cellulose nanofibrils effectively avoids the dendrite and HER, providing valuable guidelines for the practical application of zinc‐ion batteries.
Functionalizing and nano‐engineering strategies are utilized to explore cellulose as a novel solid‐state Zn2+ conductor (Zn‐CCNF@XG). The introduction of −COOH is favorable to Zn2+ rapid ion‐hopping with low energy barrier and high ionic conductivity (1.17 × 10−4 S cm−1), showing an efficient and instructive strategy for high ionic conductivity, ionic transference number, and stability of SSEs.
Solid‐state lithium–oxygen (Li–O2) batteries are considered as the next‐generation solution for high‐safety energy storage systems to overcome the persistent problems associated with liquid battery ...systems. However, the absence of stable solid‐state electrolytes (SSEs) and the design complexity of functional solid‐state cathode (SSC) remains a fundamental challenge. Here, a high‐performance solid‐state Li–O2 battery is presented with Li‐ion‐conducted UiO‐67 (UiO‐67‐Li) as SSEs and UiO‐67‐Li@reduced graphene oxide (rGO) aerogel integrated structure as SSC. The UiO‐67‐Li SSEs reveal exceptional conductivity (0.64 mS cm−1 at 25 °C) along with high chemical/electrochemical robustness. Furthermore, the prepared UiO‐67‐Li@rGO aerogel exhibits continuous and abundant Li+/e− transfer and O2 diffusion channels. Benefiting from the unique chemical properties of the UiO‐67‐Li SSEs layer, the solid‐state Li–O2 battery achieves suppression of anode dendrite formation, resistance to air‐corrosion, and presence of multiple low‐impedance wetting interfaces including anode/electrolyte and electrolyte/cathode. This ingenious arrangement endows the solid‐state Li–O2 battery with low overpotential (0.8 V), superior rate capability, and stable cycling life (up to 115 cycles). This novel design and exciting result will open up one avenue for the development of MOF‐based SSEs and cathodes for high‐performance solid‐state Li–O2 batteries and other solid‐state energy‐storage devices.
For the first time, a novel integrated solid‐state electrolyte‐cathode structure based on Li‐ion‐conducted UiO‐67 is fabricated, successfully solving the tough problems in solid‐state lithium–oxygen batteries including large resistance, low catalytic activity, and limited triple‐phase boundaries. The elaborated design and achieved electrochemical properties open up a new avenue in constructing high‐performance solid‐state lithium–oxygen batteries.
Metal oxide based gas sensors should mostly work at high temperatures; the high working temperature is associated with safety concerns and high energy consumption, which makes portable and wearable ...devices almost impossible, and the inhomogeneous temperature distribution over a sensor also has a detrimental effect on the device performance. However, all the above problems can be effectively resolved by using visible light-excited sensors working at room temperature. By depositing an array of well-aligned In2O3 nanowires on polyimide (PI) substrates, we fabricate flexible and transparent sensors that achieve room temperature gas sensing using visible light as the excitation source. The detection limit to NO2 is as low as 10 ppb under illumination using both monochromatic (blue) and polychromatic (white) light sources. The sensing performance remains consistent after repetitive bending and long-term operation. Remarkably, the sensor exhibits recoverable response to 500 ppb NO2 even under the illumination of an iPhone screen with a low irradiance of 0.56 W m−2. Through a systematic study of the interaction between the photoelectric and gas sensing properties of the materials, we also explore the mechanism of photo-induced gas sensing reactions at room temperature. This work will lay the foundation for gas sensors that can be used in portable and wearable devices.
Abstract
Rechargeable lithium−oxygen (Li−O
2
) batteries with high theoretical energy density are considered as promising candidates for portable electronic devices and electric vehicles, whereas ...their commercial application is hindered due to poor cyclic stability caused by the sluggish kinetics and cathode passivation. Herein, the intrinsic stress originated from the growth and decomposition of the discharge product (lithium peroxide, Li
2
O
2
) is employed as a microscopic pressure resource to induce the built‐in electric field, further improving the reaction kinetics and interfacial Lithium ion (Li
+
) transport during cycling. Piezopotential caused by the intrinsic stress‐strain of solid Li
2
O
2
is capable of providing the driving force for the separation and transport of carriers, enhancing the Li
+
transfer, and thus improving the redox reaction kinetics of Li−O
2
batteries. Combined with a variety of in situ characterizations, the catalytic mechanism of barium titanate (BTO), a typical piezoelectric material, was systematically investigated, and the effect of stress‐strain transformation on the electrochemical reaction kinetics and Li
+
interface transport for the Li−O
2
batteries is clearly established. The findings provide deep insight into the surface coupling strategy between intrinsic stress and electric fields to regulate the electrochemical reaction kinetics behavior and enhance the interfacial Li
+
transport for battery system.
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