Search

Uncontrollable interfacial side reactions generated from common aqueous electrolytes, just like the hydrogen evolution reaction (HER) and dendrite growth, have severely prevented the practical application of zinc‐ion batteries (ZIBs). Solid‐state ZIBs are considered to be an efficient strategy by adopting high‐quality solid‐state electrolytes (SSEs). Here, by confining deep eutectic electrolyte (DEE) into the nanochannels of metal‐organic framework (MOF)‐PCN‐222, a stable DEE@PCN‐222 SSE with internal Zn2+ transport channels was obtained. A distinctive ion‐transport network composed of DEE and PCN‐222 in the interior of DEE@PCN‐222 realizes the efficient Zn2+ conduction, contributing to high ionic conductivity of 3.13×10−4 S cm−1 at room temperature, low activation energy of 0.12 eV, and a high Zn2+ transference number of 0.74. Furthermore, experimental and theoretical investigations demonstrate that DEE@PCN‐222 with its unique channel structure could homogeneously regulate the Zn2+ distribution and effectively alleviate the side reactions. Highly reversible Zn plating/stripping performance of 2476 h can be realized by the SSE. The solid‐state ZIBs show a specific capacity of 306 mAh g−1 and display cycling stability of 517 cycles. This unique design concept provides a new perspective in realizing the high‐safety and high‐performance ZIBs. [ABSTRACT FROM AUTHOR]

The light‐assisted strategy is considered as an effective way to reduce the overpotential of lithium‐oxygen (Li─O2) batteries, however, the generated solid discharge products are prone to cover active sites of the solid‐state photocatalyst, causing the premature death of the cell. Herein, for the first time, the feasibility of soluble photocatalysts in Li─O2 battery system using Iron (II) Phthalocyanine (FePc) is verified. A micro reaction channel is constructed between the sp2‐carbon cathode and the soluble photocatalyst‐phthalein iron through π–π interaction, which can effectively increase the three‐phase reaction interface, facilitating the rapid separation and the transportation of photogenerated electrons and holes, thus improving the photocatalytic efficiency and the reaction kinetics of Li─O2 battery. Moreover, the FePc soluble photocatalysts induced the dual growth modes of surface growth and solution‐mediated growth pathways for the discharge products lead to an additional discharge capacity in the Li─O2 battery. Accordingly, the battery exhibits a lower overpotential of 0.33 V between discharge and charge plateaus at a current density of 0.01 mA cm−2, displaying the excellent cyclic stability (remaining a round‐trip efficiency of 81.1% after 130 cycles). The novel strategy provides new approaches for the construction of the light‐assisted Li─O2 batteries with reduced overpotential and boosted energy efficiency. [ABSTRACT FROM AUTHOR]

Li‐N2 batteries have received widespread attention for their potential to integrate N2 fixation, energy storage, and conversion. However, because of the low activity and poor stability of cathode catalysts, the electrochemical performance of Li‐N2 batteries is suboptimal, and their electrochemical reversibility has rarely been proven. In this study, a novel bifunctional photo‐assisted Li‐N2 battery system was established by employing a plasmonic Au nanoparticles (NPs)‐modified defective carbon nitride (Au‐Nv‐C3N4) photocathode. The Au‐Nv‐C3N4 exhibits strong light‐harvesting, N2 adsorption, and N2 activation abilities, and the photogenerated electrons and hot electrons are remarkably beneficial for accelerating the discharge and charge reaction kinetics. These advantages enable the photo‐assisted Li‐N2 battery to achieve a low overpotential of 1.32 V, which is the lowest overpotential reported to date, as well as superior rate capability and prolonged cycle stability (≈500 h). Remarkably, a combination of theoretical and experimental results demonstrates the high reversibility of the photo‐assisted Li‐N2 battery. The proposed novel strategy for developing efficient cathode catalysts and fabricating photo‐assisted battery systems breaks through the overpotential bottleneck of Li‐N2 batteries, providing important insights into the mechanism underlying N2 fixation and storage. [ABSTRACT FROM AUTHOR]

The high overpotential caused by the slow kinetics of oxygen reduction (ORR) and oxygen evolution (OER) has greatly limited the practical application of lithium‐oxygen (Li−O2) batteries. The adoption of force‐field‐assisted system based on a newly developed piezocatalysis is promising in reducing the overpotential. Herein, a force‐assisted Li−O2 battery is first established by employing MoS2/Pd nanocomposite cathode, in which the piezoelectric polarization as well as built‐in electric field are formed in MoS2 piezoelectric catalyst under ultrasound activation, leading to the continuously separated electrons and holes to enhance the ORR and OER kinetics. Moreover, the introduction of Pd can promote the electrons transfer and further inhibit the complexation of electron–hole pairs, contributing to enhanced catalytic activity in the decomposition/generation of discharge products, resulting in reduced discharge/charge overpotentials. Thus, the force‐assisted MoS2/Pd‐based Li−O2 battery is capable of adjusting the output and input energies by the assisted ultrasonic wave. An ultra‐low charging platform of 2.86 V and a high discharging platform of 2.77 V are achieved. The proposed unique force‐assisted strategy can also be applied to lithium carbon dioxide battery system through the effective reduction and separation of CO2 and CO32−, providing significant insights in achieving efficient energy conversion for metal−air batteries. [ABSTRACT FROM AUTHOR]

Metal–organic frameworks (MOFs) with accurately directional and well‐ordered channels are considered ideal solid‐state Li‐ion conductors and are expected to be utilized in solid‐state lithium–oxygen (Li–O2) batteries to achieve rechargeable batteries with high energy density. However, the instability of MOFs toward air and lithium metal has become a crucial problem to overcome. Herein, a breakthrough is first realized in overcoming these challenges by utilizing cationic MOF (CMOF) as an advanced Li‐ion conductor. Benefiting from the positively charged sites in the CMOF, an outstanding Li+ conductivity of 6.45 × 10−4 S cm−1 at room temperature, a low activation energy of 0.15 eV, and a high transference number of 0.59 are achieved. In particular, the CMOF shows high flame retardancy, H2O, and O2− stability, which are key factors that affect the battery performance of Li–O2 batteries. Such extraordinary Li+ transport makes the assembled solid‐state Li–O2 battery cycle up to 790 h with a low overpotential of 1.09 V. The proposed novel directional modification strategy is of great significance to developing high‐performance SSEs for solid‐state Li–O2 batteries and other lithium batteries. [ABSTRACT FROM AUTHOR]

Rechargeable lithium–oxygen batteries (LOBs) are considered to be one of the most promising energy storage systems. However, the use of reactive lithium (Li) metal and the formation of Li dendrites during battery operation would lead to serious safety concerns, especially when flammable liquid electrolytes are utilized. Herein, superior metal–organic framework (MOF) glass‐based solid‐state electrolytes (SSEs) is developed for stable all‐solid‐state LOBs (SSLOBs). These non‐flammable and boundary‐free MOF glass SSEs are capable of suppressing the dendrite growth and exhibiting long‐term Li stripping/plating stability, contributing to superior Li+ conductivity (5 × 10−4 S cm−1 at 20 °C), high Li+ transference number (0.86), and good electrochemical stability. It is discovered that discharge product deposition behavior in the solid‐solid interface can be well regulated by the ion/electron mixed conducted cathode fabricated with MOF glass SSEs and electronic conductive polymers. As a result, the SSLOBs can be stably recharged for 400 cycles with a low polarization gap and deliver a high capacity of 13552 mAh g−1. The development of this proposed MOF glass displays great application potential in energy storage systems with good safety and high energy density. [ABSTRACT FROM AUTHOR]

Solid‐state lithium (Li) batteries promise both high energy density and safety while existing solid‐state electrolytes (SSEs) fail to satisfy the rigorous requirements of battery operations. Herein, novel polyoxometalate SSEs, Li3PW12O40 and Li3PMo12O40, are synthesized, which exhibit excellent interfacial compatibility with electrodes and chemical stability, overcoming the limitations of conventional SSEs. A high ionic conductivity of 0.89 mS cm−1 and a low activation energy of 0.23 eV are obtained due to the optimized three‐dimensional Li+ migration network of Li3PW12O40. Li3PW12O40 exhibits a wide window of electrochemical stability that can both accommodate the Li anode and high‐voltage cathodes. As a result, all‐solid‐state Li metal batteries fabricated with Li/Li3PW12O40/LiNi0.5Co0.2Mn0.3O2 display a stable cycling up to 100 cycles with a cutoff voltage of 4.35 V and an areal capacity of more than 4 mAh cm−2, as well as a cost‐competitive SSEs price of $5.68 kg−1. Moreover, Li3PMo12O40 homologous to Li3PW12O40 was obtained via isomorphous substitution, which formed a low‐resistance interface with Li3PW12O40. Applications of Li3PW12O40 and Li3PMo12O40 in Li‐air batteries further demonstrate that long cycle life (650 cycles) can be achieved. This strategy provides a facile, low‐cost strategy to construct efficient and scalable solid polyoxometalate electrolytes for high‐energy solid‐state Li metal batteries. [ABSTRACT FROM AUTHOR]

Solid‐state electrolytes (SSEs) with high ionic conductivity and superior stability are considered to be a key technology for the safe operation of solid‐state lithium batteries. However, current SSEs are incapable of meeting the requirements for practical solid‐state lithium batteries. Here we report a general strategy for achieving high‐performance SSEs by engineering polymers of intrinsic microporosity (PIMs). Taking advantage of the interconnected ion pathways generated from the ionizable groups, high ionic conductivity (1.06×10−3 S cm−1 at 25 °C) is achieved for the PIMs‐based SSEs. The mechanically strong (50.0 MPa) and non‐flammable SSEs combine the two superiorities of outstanding Li+ conductivity and electrochemical stability, which can restrain the dendrite growth and prevent Li symmetric batteries from short‐circuiting even after more than 2200 h cycling. Benefiting from the rational design of SSEs, PIMs‐based SSEs Li‐metal batteries can achieve good cycling performance and superior feasibility in a series of withstand abuse tests including bending, cutting, and penetration. Moreover, the PIMs‐based SSEs endow high specific capacity (11307 mAh g−1) and long‐term discharge/charge stability (247 cycles) for solid‐state Li−O2 batteries. The PIMs‐based SSEs present a powerful strategy for enabling safe operation of high‐energy solid‐state batteries. [ABSTRACT FROM AUTHOR]