A Novel Phase of Li15Si4 Synthesized under Pressure

Li₁₅Si₄, the only crystalline phase that forms during lithiation of the Si anode in lithium‐ion batteries, is found to undergo a structural transition to a new phase at 7 GPa. Despite the large unit cell of Li₁₅Si₄ (152 atoms in the unit cell), ab initio evolutionary metadynamics (using the USPEX code) successfully predicts the atomic structure of this new phase (β‐Li₁₅Si₄), which has an orthorhombic structure with an Fdd2 space group. In the new β‐Li₁₅Si₄ phase Si atoms are isolated by Li atoms analogous to the original cubic phase (α‐Li₁₅Si₄), whereas the atomic packing is more efficient owing to the higher Si? Li coordination number and shorter Si? Li, Li? Li bonds. β‐Li₁₅Si₄ has substantially larger elastic moduli compared with α‐Li₁₅Si₄, and has a good electrical conductivity. As a result, β‐Li₁₅Si₄ has superior resistance to deformation and fracture under stress. The theoretical volume expansion of Si would decrease 25% if it transforms to β‐Li₁₅Si₄, instead of α‐Li₁₅Si₄, during lithiation. Moreover, β‐Li₁₅Si₄ can be recovered back to ambient pressure, providing opportunities to further investigate its properties and potential applications.     

Amorphous Carbon Coated High Grain Boundary Density Dual Phase Li4Ti5O12‐TiO2: A Nanocomposite Anode Material for Li‐Ion Batteries

This work introduces an effective, inexpensive, and large‐scale production approach to the synthesis of a carbon coated, high grain boundary density, dual phase Li₄Ti₅O₁₂‐TiO₂ nanocomposite anode material for use in rechargeable lithium‐ion batteries. The microstructure and morphology of the Li₄Ti₅O₁₂‐TiO₂‐C product were characterized systematically. The Li₄Ti₅O₁₂‐TiO₂‐C nanocomposite electrode yielded good electrochemical performance in terms of high capacity (166 mAh g^?1 at a current density of 0.5 C), good cycling stability, and excellent rate capability (110 mAh g^?1 at a current density of 10 C up to 100 cycles). The likely contributing factors to the excellent electrochemical performance of the Li₄Ti₅O₁₂‐TiO₂‐C nanocomposite could be related to the improved morphology, including the presence of high grain boundary density among the nanoparticles, carbon layering on each nanocrystal, and grain boundary interface areas embedded in a carbon matrix, where electronic transport properties were tuned by interfacial design and by varying the spacing of interfaces down to the nanoscale regime, in which the grain boundary interface embedded carbon matrix can store electrolyte and allows more channels for the Li+ ion insertion/extraction reaction. This research suggests that carbon‐coated dual phase Li₄Ti₅O₁₂‐TiO₂ nanocomposites could be suitable for use as a high rate performance anode material for lithium‐ion batteries.     

Sodium Storage and Transport Properties in Layered Na2Ti3O7 for Room‐Temperature Sodium‐Ion Batteries

Layered sodium titanium oxide, Na₂Ti₃O₇, is synthesized by a solid‐state reaction method as a potential anode for sodium‐ion batteries. Through optimization of the electrolyte and binder, the microsized Na₂Ti₃O₇ electrode delivers a reversible capacity of 188 mA h g^?1 in 1 M NaFSI/PC electrolyte at a current rate of 0.1C in a voltage range of 0.0–3.0 V, with sodium alginate as binder. The average Na storage voltage plateau is found at ca. 0.3 V vs. Na⁺/Na, in good agreement with a first‐principles prediction of 0.35 V. The Na storage properties in Na₂Ti₃O₇ are investigated from thermodynamic and kinetic aspects. By reducing particle size, the nanosized Na₂Ti₃O₇ exhibits much higher capacity, but still with unsatisfied cyclic properties. The solid‐state interphase layer on Na₂Ti₃O₇ electrode is analyzed. A zero‐current overpotential related to thermodynamic factors is observed for both nano‐ and microsized Na₂Ti₃O₇. The electronic structure, Na⁺ ion transport and conductivity are investigated by the combination of first‐principles calculation and electrochemical characterizations. On the basis of the vacancy‐hopping mechanism, a quasi‐3D energy favorable trajectory is proposed for Na₂Ti₃O₇. The Na⁺ ions diffuse between the TiO₆ octahedron layers with pretty low activation energy of 0.186 eV.     

Challenges of Spinel Li4Ti5O12 for Lithium‐Ion Battery Industrial Applications

Rechargeable lithium‐ion batteries (LIBs) offer the advantages of having great electrical energy storage and increased continuous and pulsed power output capabilities, which enable their applications in grid energy storage and electric vehicles (EVs). For safety, high power and durability considerations, spinel Li₄Ti₅O₁₂ is one of the most appealing potential candidate as an anode material for power LIBs due to its excellent cycling stability and thermal stability. However, there are still a number of challenges remaining for Li₄Ti₅O₁₂ battery applications. Herein, an updated overview of the latest advances in Li₄Ti₅O₁₂ research is provided and key challenges for its future development (i.e., fast‐charging, specific capacity, swelling, interface chemistry, matching cathode and electrolyte as well as batteries design and manufacturing) are highlighted.     

Conductive Li3.08Cr0.02Si0.09V0.9O4 Anode Material: Novel “Zero‐Strain” Characteristic and Superior Electrochemical Li+ Storage

“Zero‐strain” compounds are ideal energy‐storage materials for long‐term cycling because they present negligible volume change and significantly reduce the mechanically induced deterioration during charging–discharging. However, the explored “zero‐strain” compounds are very limited, and their energy densities are low. Here, γ phase Li_3.08Cr_0.02Si_0.09V_0.9O₄ (γ‐LCSVO) is explored as an anode compound for lithium‐ion batteries, and surprisingly its “zero‐strain” Li⁺ storage during Li⁺ insertion–extraction is found through using various state‐of‐the‐art characterization techniques. Li⁺ sequentially inserts into the 4c(1) and 8d sites of γ‐LCSVO, but its maximum unit‐cell volume variation is only ≈0.18%, the smallest among the explored “zero‐strain” compounds. Its mean strain originating from Li⁺ insertion is only 0.07%. Consequently, both γ‐LCSVO nanowires (γ‐LCSVO‐NW) and micrometer‐sized particles (γ‐LCSVO‐MP) exhibit excellent cycling stability with 90.1% and 95.5% capacity retention after as long as 2000 cycles at 10C, respectively. Moreover, γ‐LCSVO‐NW and γ‐LCSVO‐MP respectively deliver large reversible capacities of 445.7 and 305.8 mAh g^?1 at 0.1C, and retain 251.2 and 78.4 mAh g^?1 at 10C. Additionally, γ‐LCSVO shows a suitably safe operating potential of ≈1.0 V, significantly lower than that of the famous “zero‐strain” Li₄Ti₅O₁₂ (≈1.6 V). These merits demonstrate that γ‐LCSVO can be a practical anode compound for stable, high‐energy, fast‐charging, and safe Li⁺ storage.     

Low‐Temperature Reduction Strategy Synthesized Si/Ti3C2 MXene Composite Anodes for High‐Performance Li‐Ion Batteries

Silicon is attracting enormous attention due to its theoretical capacity of 4200 mAh g^?1 as an anode for Li‐ion batteries (LIBs). It is of fundamental importance and challenge to develop low‐temperature reaction route to controllably synthesize Si/Ti₃C₂ MXene LIBs anodes. Herein, a novel and efficient strategy integrating in situ orthosilicate hydrolysis and a low‐temperature reduction process to synthesize Si/Ti₃C₂ MXene composites is reported. The hydrolysis of tetraethyl orthosilicate leads to homogenous nucleation and growth of SiO₂ nanoparticles on the surface of Ti₃C₂ MXene. Subsequently, SiO₂ nanoparticles are reduced to Si via a low‐temperature (200 °C) reduction route. Importantly, Ti₃C₂ MXene not only provides fast transfer channels for Li⁺ and electrons, but also relieves volume expansion of Si during cycling. Moreover, the characteristics of excellent pseudocapacitive performance and high conductivity of Ti₃C₂ MXene can synergistically contribute to the enhancement of energy storage performance. As expected, Ti₃C₂/Si anode exhibits an outstanding specific capacity of 1849 mAh g^?1 at 100 mA g^?1, even retaining 956 mAh g^?1 at 1 A g^?1. The low‐temperature synthetic route to Si/Ti₃C₂ MXene electrodes and involved battery‐capacitive dual‐model energy storage mechanism has potential in the design of novel high‐performance electrodes for energy storage devices.     

Interface‐Engineered All‐Solid‐State Li‐Ion Batteries Based on Garnet‐Type Fast Li+ Conductors

All‐solid‐state Li‐ion batteries based on Li₇La₃Zr₂O₁₂ (LLZO) garnet structures require novel electrode assembly strategies to guarantee a proper Li⁺ transfer at the electrode–electrolyte interfaces. Here, first stable cell performances are reported for Li‐garnet, c‐Li_6.25Al_0.25La₃Zr₂O₁₂, all‐solid‐state batteries running safely with a full ceramics setup, exemplified with the anode material Li₄Ti₅O₁₂. Novel strategies to design an enhanced Li⁺ transfer at the electrode–electrolyte interface using an interface‐engineered all‐solid‐state battery cell based on a porous garnet electrolyte interface structure, in which the electrode material is intimately embedded, are presented. The results presented here show for the first time that all‐solid‐state Li‐ion batteries with LLZO electrolytes can be reversibly charge–discharge cycled also in the low potential ranges (≈1.5 V) for combinations with a ceramic anode material. Through a model experiment, the interface between the electrode and electrolyte constituents is systematically modified revealing that the interface engineering helps to improve delivered capacities and cycling properties of the all‐solid‐state Li‐ion batteries based on garnet‐type cubic LLZO structures.     

Research Progress on Negative Electrodes for Practical Li‐Ion Batteries: Beyond Carbonaceous Anodes

Research activities related to the development of negative electrodes for construction of high‐performance Li‐ion batteries (LIBs) with conventional cathodes such as LiCoO₂, LiFePO₄, and LiMn₂O₄ are described. The anode materials are classified in to three main categories, insertion, conversion, and alloying type, based on their reactivity with Li. Although numerous materials have been proposed (i.e., for half‐cell assembly), few of them have reached commercial applications, apart from graphite, Li₄Ti₅O₁₂, Si, and Sn‐Co‐C. This clearly demonstrates that full‐cell studies are desperately needed rather than just characterizing materials in half‐cell assemblies. Additionally, the performance of such anodes in practical Li‐ion configurations (full‐cell) is much more important than merely proposing materials for LIBs. Irreversible capacity loss, huge volume variation, unstable solid electrolyte interface layer formation, and poor cycleability are the main issues for conversion and alloy type anodes. This review addresses how best to circumvent the mentioned issues during the construction of Li‐ion cells and the future prospects of such anodes are described in detail.     

Boosting Superior Lithium Storage Performance of Alloy‐Based Anode Materials via Ultraconformal Sb Coating–Derived Favorable Solid‐Electrolyte Interphase

Alloy materials such as Si and Ge are attractive as high‐capacity anodes for rechargeable batteries, but such anodes undergo severe capacity degradation during discharge–charge processes. Compared to the over‐emphasized efforts on the electrode structure design to mitigate the volume changes, understanding and engineering of the solid‐electrolyte interphase (SEI) are significantly lacking. This work demonstrates that modifying the surface of alloy‐based anode materials by building an ultraconformal layer of Sb can significantly enhance their structural and interfacial stability during cycling. Combined experimental and theoretical studies consistently reveal that the ultraconformal Sb layer is dynamically converted to Li₃Sb during cycling, which can selectively adsorb and catalytically decompose electrolyte additives to form a robust, thin, and dense LiF‐dominated SEI, and simultaneously restrain the decomposition of electrolyte solvents. Hence, the Sb‐coated porous Ge electrode delivers much higher initial Coulombic efficiency of 85% and higher reversible capacity of 1046 mAh g^?1 after 200 cycles at 500 mA g^?1, compared to only 72% and 170 mAh g^?1 for bare porous Ge. The present finding has indicated that tailoring surface structures of electrode materials is an appealing approach to construct a robust SEI and achieve long‐term cycling stability for alloy‐based anode materials.     

Ultrathin Li4Ti5O12 Nanosheet Based Hierarchical Microspheres for High‐Rate and Long‐Cycle Life Li‐Ion Batteries

Ultrathin Li₄Ti₅O₁₂ nanosheet based hierarchical microspheres are synthesized through a three‐step hydrothermal procedure. The average thickness of the Li₄Ti₅O₁₂ sheets is only ≈(6.6 ± 0.25) nm and the specific surface area of the sample is 178 m² g^?1. When applied into lithium ion batteries as anode materials, the hierarchical Li₄Ti₅O₁₂ microspheres exhibit high specific capacities at high rates (156 mA h g^?1 at 20 C, 150 mA h g^?1 at 50 C) and maintain a capacity of 126 mA h g^?1 after 3000 cycles at 20 C. The results clearly suggest that the utility of hierarchical structures based on ultrathin nanosheets can promote the lithium insertion/extraction reactions in Li₄Ti₅O₁₂. The obtained hierarchical Li₄Ti₅O₁₂ with ultrathin nanosheets and large specific surface area can be perfect anode materials for the lithium ion batteries applied in high power facilities, such as electric vehicles and hybrid electric vehicles.     

Reducing Capacity and Voltage Decay of Co‐Free Li1.2Ni0.2Mn0.6O2 as Positive Electrode Material for Lithium Batteries Employing an Ionic Liquid‐Based Electrolyte

Lithium‐rich layered oxides (LRLOs) exhibit specific capacities above 250 mAh g^?1, i.e., higher than any of the commercially employed lithium‐ion‐positive electrode materials. Such high capacities result in high specific energies, meeting the tough requirements for electric vehicle applications. However, LRLOs generally suffer from severe capacity and voltage fading, originating from undesired structural transformations during cycling. Herein, the eco‐friendly, cobalt‐free Li_1.2Ni_0.2Mn_0.6O₂ (LRNM), offering a specific energy above 800 Wh kg^?1 at 0.1 C, is investigated in combination with a lithium metal anode and a room temperature ionic liquid‐based electrolyte, i.e., lithium bis(trifluoromethanesulfonyl)imide and N‐butyl‐N‐methylpyrrolidinium bis(fluorosulfonyl)imide. As evidenced by electrochemical performance and high‐resolution transmission electron microscopy, X‐ray photoelectron spectroscopy, and online differential electrochemical mass spectrometry characterization, this electrolyte is capable of suppressing the structural transformation of the positive electrode material, resulting in enhanced cycling stability compared to conventional carbonate‐based electrolytes. Practically, the capacity and voltage fading are significantly limited to only 19% and 3% (i.e., lower than 0.2 mV per cycle), respectively, after 500 cycles. Finally, the beneficial effect of the ionic liquid‐based electrolyte is validated in lithium‐ion cells employing LRNM and Li₄Ti₅O₁₂. These cells achieve a promising capacity retention of 80% after 500 cycles at 1 C.     

Synthesis,characterization and luminescence of europium perchlorate with MABA‐Si complex and coating structure SiO2@Eu(MABA‐Si) luminescence nanoparticles

This article reports a novel category of coating structure SiO₂@Eu(MABA‐Si) luminescence nanoparticles (NPs) consisting of a unique organic shell, composed of perchlorate europium(III) complex, and an inorganic core, composed of silica. The binary complex Eu(MABA‐Si)₃·(ClO₄)₃·5H₂O was synthesized using HOOCC₆H₄N(CONH(CH₂)₃Si(OCH₂CH₃)₃)₂ (MABA‐Si) and was used as a ligand. Furthermore, the as‐prepared silica NPs were successfully coated with the ‐Si(OCH₂CH₃)₃ group of MABA‐Si to form Si–O–Si chemical bonds by means of the hydrolyzation of MABA‐Si. The binary complexes were characterized by elemental analysis, molar conductivity and coordination titration analysis. The results indicated that the composition of the binary complex was Eu(MABA‐Si)₃·(ClO₄)₃·5H₂O. Coating structure SiO₂@Eu(MABA‐Si) NPs were characterized using transmission electron microscopy (TEM), scanning electron microscopy (SEM) and infrared (IR) spectra. Based on the SEM and TEM measurements, the diameter of core‐SiO₂ particles was ~400 and 600 nm, and the thickness of the cladding layer Eu(MABA‐Si) was ~20 nm. In the binary complex Eu(MABA‐Si)₃·(ClO₄)₃·5H₂O, the fluorescence spectra illustrated that the energy of the ligand MABA‐Si transferred to the energy level for the excitation state of europium(III) ion. Coating structure SiO₂@Eu(MABA‐Si) NPs exhibited intense red luminescence compared with the binary complex. The fluorescence lifetime and fluorescence quantum efficiency of the binary complex and of the coating structure NPs were also calculated. The way in which the size of core‐SiO₂ spheres influences the luminescence was also studied. Moreover, the luminescent mechanisms of the complex were studied and explained.     

All‐Solid‐State Lithium‐Ion Microbatteries Using Silicon Nanofilm Anodes: High Performance and Memory Effect

All‐solid‐state thin film lithium batteries are promising devices to power the next generations of autonomous microsystems. Nevertheless, some industrial constraints such as the resistance to reflow soldering (260 °C) and to short‐circuiting necessitate the replacement of the lithium anode. In this study, a 2 V lithium‐ion system based on amorphous silicon nanofilm anodes (50–200 nm thick), a LiPON electrolyte, and a new lithiated titanium oxysulfide cathode Li_1.2TiO_0.5S_2.1 is prepared by sputtering. The determination of the electrochemical behavior of each active material and of whole systems with different configurations allows the highlighting of the particular behavior of the Li_xSi electrode and the understanding of its consequences on the performance of Li‐ion cells. Lithium‐ion microbatteries processed with industrial tools and embedded in microelectronic packages exhibit particularly high cycle life (?0.006% cycle^?1), ultrafast charge (80% capacity in 1 min), and tolerate both short‐circuiting and reflow soldering. Moreover, the perfect stability of the system allows the assignment of some modifications of the voltage curve and a slow and reversible capacity fade occurring in specific conditions, to the formation of Li₁₅Si₄ and to the expression of a “memory effect.” These new findings will help to optimize the design of future Li‐ion systems using nanosized silicon anodes.     

Superior Sodium Storage in Na2Ti3O7 Nanotube Arrays through Surface Engineering

Sodium‐ion batteries have attracted extraordinary attention owing to their low cost and raw materials in abundance. A major challenge of practical implementation is the lack of accessible and affordable anodes that can reversibly store a substantial amount of Na ions in a fast and stable manner. It is reported that surface engineered sodium titanate (Na₂Ti₃O₇) nanotube arrays directly grown on Ti substrates can serve as efficient anodes to meet those stringent requirements. The fabrication of the nanotube arrays involves hydrothermal growing of Na₂Ti₃O₇ nanotubes, surface deposition of a thin layer of TiO₂, and subsequent sulfidation. The resulting nanoarrays exhibit a high electrochemical Na‐storage activity that outperforms other Na₂Ti₃O₇ based materials. They deliver high reversible capacities of 221 mAh g^?1 and exhibit a superior cycling efficiency and rate capability, retaining 78 mAh g^?1 at 10 C (1770 mA g^?1) over 10 000 continuous cycles. In addition, the full cell consisting of Na₂Ti₃O₇ nanotube anode and Na_2/3(Ni_1/3Mn_2/3)O₂ cathode is capable of delivering a specific energy of ≈110 Wh kg^?1 (based on the mass of both electrodes). The surface engineering can provide useful tools in the development of high performance anode materials with robust power and cyclability.     

A High‐Crystalline NaV1.25Ti0.75O4 Anode for Wide‐Temperature Sodium‐Ion Battery

Sodium‐ion batteries with abundant and low‐cost sodium resources is a promising alternative to Li‐ion batteries in large‐scale energy applications. While the anode materials, due to their insufficient cycling life and insecure voltage, could not still satisfy the market demands, especially in the wide‐temperature fields, here, a high‐crystallinity anode material with post‐spinel structure, namely NaV_1.25Ti_0.75O₄, which always maintains excellent electrochemical performance at the widely variable temperatures, is reported. The results indicate that this anode delivers a high‐safety and ultrastable room‐temperature performance (i.e., an average output voltage of 0.7 V vs Na⁺/Na and the ultralong cycling life over 10 000 cycles) and good wide‐temperature performance (below 9% capacity variation at 60 and ?20 °C compared to that at 25 °C). These excellent achievements could benefit from the long durability and stability of 1D channels and superfast ion diffusion in a temperature‐dependent range. This finding provides a promising strategy to construct the safe and stable full‐cell prototypes and promotes the wide‐temperature application of sodium‐ion batteries.     

Li4Ti5O12 Nanoparticles Embedded in a Mesoporous Carbon Matrix as a Superior Anode Material for High Rate Lithium Ion Batteries

A mesoporous Li₄Ti₅O₁₂/C nanocomposite is synthesized by a nanocasting technique using the porous carbon material CMK‐3 as a hard template. Modified CMK‐3 template is impregnated with Li₄Ti₅O₁₂ precursor, followed by heat treatment at 750 °C for 6 h under N₂. Li₄Ti₅O₁₂ nanocrystals of up to several tens of nanometers are successfully synthesized in micrometer‐sized porous carbon foam to form a highly conductive network, as confirmed by field emission scanning electron microscopy, transmission electron microscopy, X‐ray diffraction, Raman spectroscopy, and nitrogen sorption isotherms. The composite is then evaluated as an anode material for lithium ion batteries. It exhibits greatly improved electrochemical performance compared with bulk Li₄Ti₅O₁₂, and shows an excellent rate capability (73.4 mA h g^?1 at 80 C) with significantly enhanced cycling performance (only 5.6% capacity loss after 1000 cycles at a high rate of 20 C). The greatly enhanced lithium storage properties of the mesoporous Li₄Ti₅O₁₂/C nanocomposite may be attributed to the interpenetrating conductive carbon network, ordered mesoporous structure, and the small Li₄Ti₅O₁₂ nanocrystallites that increase the ionic and electronic conduction throughout the electrode.     

Strategic Pore Architecture for Accommodating Volume Change from High Si Content in Lithium‐Ion Battery Anodes

To be a thinner and more lightweight lithium‐ion battery with high energy density, the next‐generation anode with high gravimetric and volumetric capacity is a prerequisite. In this regard, utilizing high silicon (3579 mAh g^?1) content in the electrode for the anode has been highlighted as a practically relevant approach. However, there still remains a crucial issue related to intrinsic volume expansion (>300%) of silicon upon lithiation, which can directly affect severe electrode swelling as well as accelerate its capacity fading by triggering structural degradation and electrical contact loss between particles. Herein, macropore‐exploited design, which can accommodate the volume change of high silicon content within the extended pore of graphite upon repeated cycling, is introduced. Such unique macropore‐exploited design leads to much less electrode swelling, by preserving its morphological integrity and contact between particles, than that of the comparative group with different sized pore and silicon distribution. As a result, this anode (914 mAh g^?1) demonstrates notable gravimetric (220 Wh kg^?1 at 6000 W kg^?1) and volumetric energy density (623 Wh L^?1 upon full lithiation after 100 cycles), exceeding that of a nano‐silicon blended graphite anode (127 Wh kg^?1 and 229 Wh L^?1) in the full‐cell system.     

Synthesis and photoluminescence characteristics of Sm3+‐doped Bi4Si3O12 red‐emitting phosphor

A series of novel red‐emitting Sm³⁺‐doped bismuth silicate phosphors, Bi₄Si₃O₁₂:xSm³⁺ (0.01 ≤ x ≤ 0.06), were prepared via the sol–gel route. The phase of the synthesized samples calcinated at 800 °C is isostructural with Bi₄Si₃O₁₂ according to X‐ray diffraction results. Under excitation with 405 nm light, some typical peaks of Sm³⁺ ions centered at 566, 609, 655 and 715 nm are found in the emission spectra of the Sm³⁺‐doped Bi₄Si₃O₁₂ phosphors. The strongest peak located at 609 nm is due to ⁴G_5/2–⁶H_7/2 transition of Sm³⁺. The luminescence intensity reaches its maximum value when the Sm³⁺ ion content is 4 mol%. The results suggest that Bi₄Si₃O₁₂:Sm³⁺ may be a potential red phosphor for white light‐emitting diodes. Copyright © 2016 John Wiley & Sons, Ltd.     

Integrated Intercalation‐Based and Interfacial Sodium Storage in Graphene‐Wrapped Porous Li4Ti5O12 Nanofibers Composite Aerogel

Sodium storage in both solid–liquid and solid–solid interfaces is expected to extend the horizon of sodium‐ion batteries, leading to a new strategy for developing high‐performance energy‐storage materials. Here, a novel composite aerogel with porous Li₄Ti₅O₁₂ (PLTO) nanofibers confined in a highly conductive 3D‐interconnected graphene framework (G‐PLTO) is designed and fabricated for Na storage. A high capacity of 195 mA h g^?1 at 0.2 C and super‐long cycle life up to 12 000 cycles are attained. Electrochemical analysis shows that the intercalation‐based and interfacial Na storage behaviors take effect simultaneously in the G‐PLTO composite aerogel. An integrated Na storage mechanism is proposed. This study ascribes the excellent performance to the unique structure, which not only offers short pathways for Na⁺ diffusion and conductive networks for electron transport, but also guarantees plenty of PLTO–electrolyte and PLTO–graphene interfacial sites for Na⁺ adsorption.     

Enabling High‐Energy Solid‐State Batteries with Stable Anode Interphase by the Use of Columnar Silicon Anodes

All‐solid‐state batteries (ASSBs) with silicon anodes are promising candidates to overcome energy limitations of conventional lithium‐ion batteries. However, silicon undergoes severe volume changes during cycling leading to rapid degradation. In this study, a columnar silicon anode (col‐Si) fabricated by a scalable physical vapor deposition process (PVD) is integrated in all‐solid‐state batteries based on argyrodite‐type electrolyte (Li₆PS₅Cl, 3 mS cm^?1) and Ni‐rich layered oxide cathodes (LiNi_0.9Co_0.05Mn_0.05O₂, NCM) with a high specific capacity (210 mAh g^?1). The column structure exhibits a 1D breathing mechanism similar to lithium, which preserves the interface toward the electrolyte. Stable cycling is demonstrated for more than 100 cycles with a high coulombic efficiency (CE) of 99.7–99.9% in full cells with industrially relevant areal loadings of 3.5 mAh cm^?2, which is the highest value reported so far for ASSB full cells with silicon anodes. Impedance spectroscopy revealed that anode resistance is drastically reduced after first lithiation, which allows high charging currents of 0.9 mA cm^?2 at room temperature without the occurrence of dendrites and short circuits. Finally, in‐operando monitoring of pouch cells gave valuable insights into the breathing behavior of the solid‐state cell.