In the coming years, the demand for safe electrical energy storage devices with high energy density will increase drastically due to the electrification of the transportation sector and the need for ...stationary storage for renewable energies. Advanced battery concepts like all-solid-state batteries (ASBs) are considered one of the most promising candidates for future energy storage technologies. They offer several advantages over conventional Lithium-Ion Batteries (LIBs), especially with regard to stability, safety, and energy density. Hardly any recycling studies have been conducted, yet, but such examinations will play an important role when considering raw materials supply, sustainability of battery systems, CO2 footprint, and general strive towards a circular economy. Although different methods for recycling LIBs are already available, the transferability to ASBs is not straightforward due to differences in used materials and fabrication technologies, even if the chemistry does not change (e.g., Li-intercalation cathodes). Challenges in terms of the ceramic nature of the cell components and thus the necessity for specific recycling strategies are investigated here for the first time. As a major result, a recycling route based on inert shredding, a subsequent thermal treatment, and a sorting step is suggested, and transferring the extracted black mass to a dedicated hydrometallurgical recycling process is proposed. The hydrometallurgical approach is split into two scenarios differing in terms of solubility of the ASB-battery components. Hence, developing a full recycling concept is reached by this study, which will be experimentally examined in future research.
The synthesis of crystalline, nonagglomerated, and perfectly dispersible Co3O4 nanoparticles with an average size of 3–7 nm using a solvothermal reaction in tert‐butanol is reported. The very small ...size and high dispersibility of the Co3O4 nanoparticles allow for their homogeneous deposition on mesoporous hematite layers serving as the photoactive absorber in the light‐driven water splitting reaction. This surface treatment leads to a striking photocurrent increase. While the enhancement of hematite photoanode performance by cobalt oxides is known, the preformation and subsequent application of well‐defined cobalt oxide nanoparticles are novel and allow for the treatment of arbitrarily complex hematite morphologies. Photoelectrochemical and transient absorption spectroscopy studies show that this enhanced performance is due to the suppression of surface electron–hole recombination on time scales of milliseconds to seconds.
Ultrasmall dispersible Co3O4 nanocrystals with an average size of 3–7 nm are prepared by a solvothermal reaction in tert‐butanol. The small size and high dispersibility of the nanoparticles enable their homogeneous deposition on nanostructured Sn‐doped hematite serving as a photoanode in light‐driven water splitting. This surface treatment leads to a striking photocurrent increase.
Nanostructured Group 14 semiconductors attract significant attention because of a broad range of potential applications. In their Communication on page 2441 ff., T. Fässler, D. Fattakhova‐Rohlfing et ...al. describe a general and controllable fabrication method for Ge nanomorphologies with tunable composition using the controlled reaction of Ge94− Zintl clusters to a solid germanium phase. The image was designed by Christoph Hohmann, Nanosystems Initiative Munich.
Hybrid solar cells, consisting of conjugated polymers and n‐type inorganic nanocrystals, are suggested as an alternative to organic solar cells due to the combined advantages of both organic and ...inorganic components. To improve easy solar cell fabrication, P. Müller‐Buschbaum and co‐workers introduce pre‐synthesized crystalline titania nanoparticles into the metal oxide phase to obtain more effective titania photoanodes, as described on page 1498. Cover image by Christoph Hohmann, Nano‐systems Initiative Munich (NIM).
To make ceramic based all-solid-state batteries competitive for the battery market, a shift from the separator supported cell-design for lab cells to a scalable, cathode-supported one is necessary to ...improve the energy density. Using tape casting, we were able to demonstrate for the first time all-ceramic free-standing LiCoO 2 (LCO)/Li 6.45 Al 0.05 La 3 Zr 1.6 Ta 0.4 O 12 (LLZO) mixed cathodes with high capacities and active material utilization. Further morphology engineering by introduction of a sequential layer casting enabled us to tailor the microstructure of the mixed cathodes resulting in opposite concentration gradients for the active material and the electrolyte over the thickness of the cathode. With this optimized microstructure, we were able to increase the discharge capacity of the free-standing mixed cathodes to 2.8 mA h cm −2 utilizing 99% of the theoretical capacity. For the oxide garnet-based system, both the scalable fabrication method and the achieved electrochemical performance demonstrates industrial relevance for the first time. Additionally, the obtained free-standing cathodes have sufficient mechanical stability to allow the application of hybrid and ultra-thin separators to further increase the energy density on the full cell level.
Garnet-structured Li-ion conductors are promising candidates as electrolytes for all-solid-state batteries. However, sintering of these materials is still a challenge, due to Li-loss accompanied by ...decomposition at elevated temperatures. In this study, Li5La3Ta2O12, a garnet material with reduced Li-content, was used as a model material to investigate the impact of the Li content in powder beds as well as the presence of Al either in the green bodies or in the powder beds on the properties of the resulting sintered materials. The resulting relative densities were increased by sintering in a Li-rich powder bed compared to a powder bed with identical stoichiometry. Furthermore, Al either in the source material or in the powder bed was shown to support densification, even if it is not incorporated in the structure. The highest ionic conductivity was 3.4 × 10-5 S cm-1 at 30 °C for Li5La3Ta2O12, which was sintered in a Li6.54Al0.02La3Zr1.6Ta0.4O12 powder bed.
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Highlights
A stable Zn anode was obtained by patterning Zn foil surfaces and endowing a zincphilic interface in microchannels.
The accumulation of electrons in the microchannel and the zincphilic ...interface promoted preferential heteroepitaxial Zn deposition in the microchannel region and subsequent homoepitaxial Zn deposition on the array surface.
The Zn symmetrical cells could undergo repeated plating/stripping for more than 25,000 cycles at the current densities of 10 and 20 mA cm
−2
.
The undesirable dendrite growth induced by non-planar zinc (Zn) deposition and low Coulombic efficiency resulting from severe side reactions have been long-standing challenges for metallic Zn anodes and substantially impede the practical application of rechargeable aqueous Zn metal batteries (ZMBs). Herein, we present a strategy for achieving a high-rate and long-cycle-life Zn metal anode by patterning Zn foil surfaces and endowing a Zn-Indium (Zn-In) interface in the microchannels. The accumulation of electrons in the microchannel and the zincophilicity of the Zn-In interface promote preferential heteroepitaxial Zn deposition in the microchannel region and enhance the tolerance of the electrode at high current densities. Meanwhile, electron aggregation accelerates the dissolution of non-(002) plane Zn atoms on the array surface, thereby directing the subsequent homoepitaxial Zn deposition on the array surface. Consequently, the planar dendrite-free Zn deposition and long-term cycling stability are achieved (5,050 h at 10.0 mA cm
−2
and 27,000 cycles at 20.0 mA cm
−2
). Furthermore, a Zn/I
2
full cell assembled by pairing with such an anode can maintain good stability for 3,500 cycles at 5.0 C, demonstrating the application potential of the as-prepared ZnIn anode for high-performance aqueous ZMBs.
Organized mesoporous layers of SiO2 with narrow pore size distribution centered at ca. 7 nm, which were uniformly functionalized with readily protonated amino groups, exhibit excellent permselective ...membrane properties. Their selectivity and permeability can be reversibly controlled by changing pH. The flux of hexacyanoferrate Fe(CN)6 3- anions, hexaamino-ruthenium Ru(NH3)6 3+ cations, and neutral ferrocene methanol molecules through the amino functionalized silica layers was monitored by cyclic voltammetry at different solution pH values. Depending on their charges, the flux of ions can be completely blocked or enhanced, while the permeation of uncharged species is affected adversely only in a limited extent by the change in pH. The high membrane porosity ensures fast penetration rates of the analytes and much faster response to the changes in pH compared to those of typical compact organic polymer layers. As the amino functionalized mesoporous silica layers enable the efficient separation of differently charged species from complex mixtures, they are attractive for applications in biology and medicine, where such mixtures are often encountered, e.g., for the separation of blood, urine, or sera components.
We present a novel “brick and mortar” strategy for creating highly efficient transparent TiO2 coatings for photocatalytic and photovoltaic applications. Our approach is based on the fusion of ...preformed titania nanocrystalline “bricks” through surfactant-templated sol−gel titania “mortar”, which acts as a structure-directing matrix and as a chemical glue. The similar chemical composition of both bricks and mortar leads to a striking synergy in the interaction of crystalline and amorphous components, such that crystallization is enhanced upon thermal treatment and highly porous and highly crystalline structures are formed at very mild conditions. Coatings with a broad variety of periodic mesostructures and thicknesses ranging from few nanometers to several micrometers are accessible using the same organic template, and the final structures are tunable by varying the fraction of the “bricks”. The beneficial combination of crystallinity and porosity leads to greatly enhanced activity of the films in photocatalytic processes, such as the photooxidation of NO. Acting as the active layers in dye-sensitized solar cells, films of only 2.7 μm in thickness exhibit a conversion efficiency of 6.0%.
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