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Lattice volume changes in Li-ion batteries active materials are unavoidable during electrochemical cycling, posing significant engineering challenges from the particle to the electrode level. In this study, we present an elastic framework coating designed to absorb and reversibly release strain energy associated with particle volume changes, thereby enhancing mechanical resilience at both the particle and electrode levels. This framework, composed of multiwalled carbon nanotubes (MWCNTs), is applied to nickel-rich LiNi0.9Co0.05Mn0.05O2(NCM9055) cathodes at a low loading of 0.5 wt %, effectively mitigating critical issues such as particle cracking, volume changes, and electrode thickness variations during cycling. Leveraging these advantages, an energy-dense electrode is achieved with a high active material loading of 20 mg cm–2, without the need for additional carbon additives. Demonstrated in a pouch cell format, this electrode achieves an exceptional capacity retention of 77.7% after 1000 cycles. This approach provides a comprehensive solution for designing Li-ion batteries capable of withstanding lattice volume variations, offering valuable insights for next-generation batteries technologies.

Dendritic challenges in Li metal batteries are commonly resolved using porous three-dimensional (3D) current collectors, which have a significant issue in that Li is deposited from the top (top growth) of the structure rather than from the bottom (bottom growth), failing to effectively suppress dendrite growth and volumetric expansion. We propose the structure incorporating a gradient lithiophilic seed within a 3D framework by pulse electroplating Mg, specifically targeting the near bottom to promote bottom growth and achieve dense Li deposition. This method achieves precise control over the catalytic seed size and distribution. Optimal conditions for maximizing the catalytic effect are identified. The resulting Mg-gradient porous-Cu structure exhibits superior Li-plating behavior with bottom growth, significantly reducing dendrite formation and improving cycle life. The mechanistic origin of bottom-guided Li growth is supported by DFT and 3D simulation results. This method presents a significant step forward in developing high-performance Li–metal batteries.

The adoption of Li2CuO2has drawn interest as a Li-excess cathode additive for compensating irreversible Li+loss in anodes during cycling, which would move forward high-energy-density lithium-ion batteries (LIBs). Li2CuO2provides a high irreversible capacity (>200 mAh g–1) in the first cycle and an operating voltage comparable with commercial cathode materials, but its practical use is still restricted by the structural instability and spontaneous oxygen (O2) evolution, resulting in poor overall cycling performance. It is thus crucial to reinforce the structure of Li2CuO2to make it more reliable as a cathode additive for charge compensation. Pursuing the structural stability of Li2CuO2, herein, we demonstrate cosubstitution by heteroatoms, such as nickel (Ni) and manganese (Mn), for improving the structural stability and electrochemical performance of Li2CuO2. Such an approach effectively enhances the reversibility of Li2CuO2by suppressing continuous structural degradation and O2gas evolution during cycling. Our findings provide new conceptual pathways for developing advanced cathode additives for high-energy LIBs.

Li-confinable core–shell hosts have been extensively studied because they mitigate Li dendrite growth and volume change by reducing the effective current density and storing Li inside the core space during consecutive cycling. However, despite these fascinating features, these hosts suffer from unwanted Li growth on their surface (i.e., top plating) due to the carbon shell hindering Li-ion movement especially at higher current densities and capacities, resulting in poor electrochemical performance. In this study, we propose a one-dimensional porous Li-confinable host with lithiophilic Au (Au@PHCF), which is synthesized by a scalable dual-nozzle electrospinning. Because of the well-interconnected conductive networks forming three-dimensional structure, porous shell design enabling facile Li-ion transport, and hollow core space with lithiophilic Au storing metallic Li, the Au@PHCF can suppress the Li top plating and improve the Li stripping/plating efficiency compared to their counterparts even at 5 mA cm–2, eventually achieving stable cycling performances of the LiFePO4full cell and Au@PHCF-Li symmetric cell for over 1000 and 2000 cycles, respectively. Finite element analysis reveals that the structural merit and lithiophilicity of Au enable fast reversible Li operation at the designated core space of the Au@PHCF, implying that the structural design of the Li-confinable host is crucial for the stable operation of promising Li-metal batteries at a practical test level.

A Ni3Sn4is designed to accommodate high capacity and mechanical stability as a promising anode materials for fast charging. Intrinsic electrochemical activity of Ni in Ni3Sn4is vailed using electronic structure analysis in DFT frameworks

Recently, Ni-rich layered cathode materials have become the most common material used for lithium-ion batteries. From a structural viewpoint, it is crucial to stabilize the surface structures of such materials, as they are prone to undesirable side reactions and particle cracking in which intergranular microcracks form at the particle surfaces and then propagate inside. As a simplified engineering technique for obtaining Ni-rich cathode materials with high reversibility and long-term cycling stability, we propose a facile surface coating of piezoelectric LiTaO3onto a Ni-rich cathode material to enhance the charge transfer reaction and surface structural integrity. Based on theoretical and experimental investigation, we demonstrate that this surface protection approach is effective at enhancing the reversibility and mechanical strength of Ni-rich cathode materials, leading to a stable cycle performance at up to 150 cycles, even at 60 °C. Furthermore, the piezoelectric characteristics of the surface LiTaO3can enhance the rate capability of Ni-rich cathode materials at current densities of up to 2.0C. The results of this study provide a practical insight on the development of Ni-rich cathode materials for practical use in electric vehicle applications.

Silicon-based materials are the most promising candidates to surpass the capacity limitation of conventional graphite anode for lithium ion batteries. Unfortunately, Si-based materials suffer from poor cycling performance and dimensional instability induced by the large volume changes during cycling. To resolve such problems, nanostructured silicon-based materials with delicately controlled microstructure and interfaces have been intensively investigated. Nevertheless, they still face problems related to their high synthetic cost and their limited electrochemical properties and thermal stability. To overcome these drawbacks, we demonstrate the strategic design and synthesis of a gyroid three-dimensional network in a Si@SiOx/C nanoarchitecture (3D-Si@SiOx/C) with synergetic interaction between the computational prediction and the synthetic optimization. This 3D-Si@SiOx/C exhibits not only excellent electrochemical performance due to its structural stability and superior ion/electron transport but also enhanced thermal stability due to the presence of carbon, which was formed by a cost-effective one-pot synthetic route. We believe that our rationally designed 3D-Si@SiOx/C will lead to the development of anode materials for the next-generation lithium ion batteries.

The use of high-capacity electrode materials (i.e., Si) in Li-ion batteries is hindered by their mechanical degradation. Thus, oxides (i.e., SiO2) are commonly used to obtain high expected capacities and long-term cycle performances. Despite extensive studies of the electrochemical–mechanical behaviors of high-capacity energy storage materials, the mechanical behaviors of amorphous SiO2during electrochemical reaction remain largely unknown. Here, we systematically investigate the stress evolution, electronic structure, and mechanical deformation of lithiated SiO2through first-principles computation and the finite element method. The structural and thermodynamic role of O in the amorphous Li–O–Si system is reported and compared with that in Si. Strong Si–O bonds in SiO2show high mechanical strength and brittle behavior, but as Li is inserted, the Li-rich SiO2phases become mechanically softened. The relaxation kinetics of SiO2, inducing deviatoric inelastic strains under mechanical constraints, is also compared with that of Si. The finite element model including the kinetic model for anisotropic expansion demonstrates that the long-term cycling stability of core–shell Si–SiO2nanoparticles mainly arises from the reaction kinetics and high mechanical strength of SiO2. These results provide fundamental insights into the chemomechanical behavior of SiO2for practical use.

Graphical Abstract:

Li metal has been regarded as a promising anode for rechargeable batteries with high energy densities. However, the growth of Li dendrites and severe volume changes in the Li anode still hinder its practical use. Three-dimensional (3D) host structures have recently attracted significant attention as an effective strategy to resolving these problems. Herein, we demonstrate reversible Li metal storage in carbon hosts with strong Li–host interactions derived from metal-organic frameworks (MOFs). The combined experimental and computational modeling studies reveal that galvanically displaced Ag enhances Li–host interactions and the spatial distribution characteristics of Ag play a crucial role in controlling Li storage behavior and reversibility. The atomic Ag clusters trigger the outward growth of Li from the internal pores of the host and enables stable battery cycling, whereas the surface-anchored Ag nanoparticles induce uneven Li plating on the outer surface of the carbon host, resulting in a rapid performance drop. This work provides new insights into the development of advanced host materials for reversible Li anodes by utilizing strong Li–host interactions.

The instability of organic/inorganic hybrid perovskite solar cells (PSCs) has motivated the development of the inorganic halide PSCs. However, the representative inorganic CsPbI3still suffers from phase instability in ambient air and an unfavorable wide bandgap (1.75 eV), thereby limiting its efficiency. In this study, a binary metal composition of Pb:Sn = 4:6 in CsPb1-xSnxI3is found to stabilize the cubic CsPbI3phase and reduce its bandgap. Based on the parental CsPb0.4Sn0.6I3, compositional engineering is further conducted for CsPb0.4Sn0.6I3-yBryperovskites. After introducing a suitable Br content (y = 0.6), there are remarkable improvements in the crystalline quality and a denser morphology in the perovskite films. Furthermore, in the novel inorganic CsPb0.4Sn0.6I2.4Br0.6perovskite, trap-assisted recombination is effectively suppressed, with a desirable narrow bandgap of 1.35 eV. As a result, the corresponding PSC delivered an unprecedented efficiency of 12.34%, which is the highest among the inorganic Sn-rich (Sn > 50%) PSCs reported to date. Additionally, the unencapsulated PSC demonstrates impressive long-term air stability, which exceeds the performance of 100% Pb-based inorganic CsPbI3and/or CsPbI2Br PSCs reported. This near-infrared absorbing (~930 nm) inorganic PSC with exceptional efficiency, durability and Pb-reduction generates a promising route for further progress of perovskite-based photovoltaics.