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Lithium-ion batteries (LIBs) are ubiquitous in everyday applications. However, Lithium (Li) is a limited resource on the planet and, therefore, not sustainable. As an alternative to lithium, earth-abundant and cheaper multivalent metals such as aluminum (Al) and calcium (Ca) have been actively researched in battery systems. However, finding suitable intercalation hosts for multivalent-ion batteries is urgently needed. Open-tunneled oxides represent a specific category of microparticles distinguished by the presence of integrated one-dimensional channels or nanopores. This work focuses on two promising open-tunnel oxides: Niobium Tungsten Oxide (NTO) and Molybdenum Vanadium Oxide (MoVO). The MoVO structure can accommodate a larger number of multivalent ions than NTO due to its larger surface area and different shapes. Specifically, the MoVO structure can adsorb Ca, Li, and Al ions with adsorption potentials ranging from around 4 to 5 eV. However, the adsorption potential for hexagonal channels of Al ion drops to 1.73 eV due to the limited channel area. The NTO structure exhibits an insertion/adsorption potential of 4.4 eV, 3.4 eV, and 0.9 eV for one Li, Ca, and Al, respectively. Generally, Ca ions are more readily adsorbed than Al ions in both MoVO and NTO structures. Bader charge analysis and charge density plots reveal the role of charge transfer and ion size in the insertion of multivalent ions such as Ca and Al into MoVO and NTO systems. Exploring open-tunnel oxide materials for battery applications is hindered by vast compositional possibilities. The execution of experimental trials and quantum-based simulations is not viable for addressing the challenge of locating a specific item within a large and complex set of possibilities. Therefore, it is imperative to conduct structural stability testing to identify viable combinations with sufficient pore topologies. Data mining and machine learning techniques are employed to discover innovative transitional metal oxide materials. This study compares two machine learning algorithms, one utilizing descriptors and the other employing graphs to predict the synthesizability of new materials inside a laboratory setting. The outcomes of this study offer valuable insights into the exploration of alternative naturally occurring multiscale particles. 

Alloy‐based anodes are regarded as safer and higher capacity alternatives to lithium metal and commercial graphite anodes respectively. However, their commercialization is hindered by poor stability and irreversible loss of active material during cycling. Combining non‐flammable and electrochemically stable solid‐state electrolytes with high‐capacity alloy anodes has chemo‐mechanical benefits that can address these long‐standing issues. The distinctive interfacial characteristics of solid‐state electrolytes reduce the impact of volume variation and dynamic reconstruction of the solid‐electrolyte‐interphase, thereby realizing the best of both worlds. In this perspective, the interfacial underpinnings for alloy anode based solid‐state batteries that are crucial for their success are discussed. The goal is to update the audience with key recent findings that can lay the foundation for future research work in this area. The relevant steps toward commercialization of alloy anode based solid‐state batteries are also discussed, starting from bulk and interface architectures to electrode composite preparation and final cell assembly.

 

The instability of Nickel (Ni)‐rich cathodes at high voltage is a critical bottleneck toward developing superior lithium‐ion batteries. This instability is driven by cathode‐electrolyte side reactions, causing rapid degradation, and compromising the overall cycle life. In this study, a protective coating using dispersed “magnetite (FeO.Fe₂O₃)” nanoparticles is used to uniformly decorate the surface of LiNi_0.8Co_0.1Mn_0.1O₂(NMC 811) microparticles. The modified cathode delivers significant improvement in electrochemical performance at high voltage (≈4.6 V) by suppressing deleterious electrode–electrolyte interactions. A notably higher cycle stability, rate performance, and overall energy density is realized for the coated cathode in a conventional liquid electrolyte battery. When deployed in pellet‐stacked solid‐state cells with Li₆PS₅Cl as the electrolyte, the magnetite‐coated NMC 811 showed strikingly superior cycling stability than its uncoated counterpart, proving the versatility of the chemistry. The facile surfactant‐assisted coating process developed in this work, in conjunction with the affordability, abundance, and nontoxic nature of magnetite makes this a promising approach to realize commercially viable high voltage Ni‐rich cathodes that exhibit stable performance in liquid as well as solid‐state lithium‐ion batteries.

 

Looming concerns regarding scarcity, high prices, and safety threaten the long-term use of lithium in energy storage devices. Calcium has been explored in batteries because of its abundance and low cost, but the larger size and higher charge density of calcium ions relative to lithium impairs diffusion kinetics and cyclic stability. In this work, an aqueous calcium–ion battery is demonstrated using orthorhombic, trigonal, and tetragonal polymorphs of molybdenum vanadium oxide (MoVO) as a host for calcium ions. Orthorhombic and trigonal MoVOs outperform the tetragonal structure because large hexagonal and heptagonal tunnels are ubiquitous in such crystals, providing facile pathways for calcium–ion diffusion. For trigonal MoVO, a specific capacity of ∼203 mAh g −1 was obtained at 0.2C and at a 100 times faster rate of 20C, an ∼60 mAh g −1 capacity was achieved. The open-tunnel trigonal and orthorhombic polymorphs also promoted cyclic stability and reversibility. A review of the literature indicates that MoVO provides one of the best performances reported to date for the storage of calcium ions. 

Orthorhombic BaZrS 3 is a potential optoelectronic material with prospective applications in photovoltaic and thermoelectric devices. While efforts exist on understanding the effects of elemental substitution and material stability, fundamental knowledge on the electronic transport properties are sparse. We employ first principles calculations to examine the electronic band structure and optical band gap and interrogate the effect of electron transport on electrical and thermal conductivities, and Seebeck coefficient, as a function of temperature and chemical potential. Our results reveal that BaZrS 3 has a band gap of 1.79 eV in proximity of the optimal 1.35 eV recommended for single junction photovoltaics. An absorption coefficient of 3 × 10 5 cm −1 at photon energies of 3 eV is coupled with an early onset to optical absorption at 0.5 eV, significantly below the optical band gap. The carrier effective mass being lower for electrons than holes, we find the Seebeck coefficient to be higher for holes than electrons. A notable (≈1.0 at 300 K) upper limit to the thermoelectric figure of merit, obtained due to high Seebeck coefficient (3000 μV K −1 ) and ultra-low electron thermal conductivity, builds promise for BaZrS 3 as a thermoelectric.