All‐solid‐state lithium batteries (ASSLBs) are considered as the next generation electrochemical energy storage devices because of their high safety and energy density, simple packaging, and wide ...operable temperature range. The critical component in ASSLBs is the solid‐state electrolyte. Among all solid‐state electrolytes, the sulfide electrolytes have the highest ionic conductivity and favorable interface compatibility with sulfur‐based cathodes. The ionic conductivity of sulfide electrolytes is comparable with or even higher than that of the commercial organic liquid electrolytes. However, several critical challenges for sulfide electrolytes still remain to be solved, including their narrow electrochemical stability window, the unstable interface between the electrolyte and the electrodes, as well as lithium dendrite formation in the electrolytes. Herein, the emerging sulfide electrolytes and preparation methods are reviewed. In particular, the required properties of the sulfide electrolytes, such as the electrochemical stabilities of the electrolytes and the compatible electrode/electrolyte interfaces are highlighted. The opportunities for sulfide‐based ASSLBs are also discussed.
All‐solid‐state lithium batteries are considered to be next‐generation devices for electrochemical energy storages due to their superiority in high safety and energy density. Sulfide electrolytes have become one of the most promising ion conductors due to their high ionic conductivities. At the same time, the favorable interface compatibility of sulfide electrolytes with sulfide‐based cathodes delivers bright prospect of all‐solid‐state lithium batteries.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Thin solid‐state electrolytes with nonflammability, high ionic conductivity, low interfacial resistance, and good processability are urgently required for next‐generation safe, high energy density ...lithium metal batteries. Here, a 3D Li6.75La3Zr1.75Ta0.25O12 (LLZTO) self‐supporting framework interconnected by polytetrafluoroethylene (PTFE) binder is prepared through a simple grinding method without any solvent. Subsequently, a garnet‐based composite electrolyte is achieved through filling the flexible 3D LLZTO framework with a succinonitrile solid electrolyte. Due to the high content of garnet ceramic (80.4 wt%) and high heat‐resistance of the PTFE binder, such a composite electrolyte film with nonflammability and high processability exhibits a wide electrochemical window of 4.8 V versus Li/Li+ and high ionic transference number of 0.53. The continuous Li+ transfer channels between interconnected LLZTO particles and succinonitrile, and the soft electrolyte/electrode interface jointly contribute to a high ambient‐temperature ionic conductivity of 1.2 × 10−4 S cm−1 and excellent long‐term stability of the Li symmetric battery (stable at a current density of 0.1 mA cm−2 for over 500 h). Furthermore, as‐prepared LiFePO4|Li and LiNi0.5Mn0.3Co0.2O2|Li batteries based on the thin composite electrolyte exhibit high discharge specific capacities of 153 and 158 mAh g−1 respectively, and desirable cyclic stabilities at room temperature.
Thin, flexible, and nonflammable composite solid electrolytes with plastic crystals in a 3D garnet‐based framework are prepared by a facile, solvent‐free method, and these unique composite solid electrolytes with high ionic conductivity and low interfacial resistance endow LiFePO4|Li and LiNi0.5Mln0.3Co0.2O2|Li cells with high discharge specific capacities, and desirable cyclic stabilities at room temperature.
Full text
Available for:
FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
All‐solid‐state lithium batteries (ASSLBs) have the potential to revolutionize battery systems for electric vehicles due to their benefits in safety, energy density, packaging, and operable ...temperature range. As the key component in ASSLBs, inorganic lithium‐ion‐based solid‐state electrolytes (SSEs) have attracted great interest, and advances in SSEs are vital to deliver the promise of ASSLBs. Herein, a survey of emerging SSEs is presented, and ion‐transport mechanisms are briefly discussed. Techniques for increasing the ionic conductivity of SSEs, including substitution and mechanical strain treatment, are highlighted. Recent advances in various classes of SSEs enabled by different preparation methods are described. Then, the issues of chemical stabilities, electrochemical compatibility, and the interfaces between electrodes and SSEs are focused on. A variety of research addressing these issues is outlined accordingly. Given their importance for next‐generation battery systems and transportation style, a perspective on the current challenges and opportunities is provided, and suggestions for future research directions for SSEs and ASSLBs are suggested.
Inorganic solid‐state electrolytes (SSEs) offer numerous advantages for the development of next‐generation batteries. The most promising advantages are the safety that benefits from the nonflammable nature of SSEs and the possibility of using a Li‐metal anode, which has highest capacity, lowest anodic potential, and is indispensable to the future success of high‐energy‐density Li–S batteries and Li–O2 battery systems.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
With increasing demands for safe, high capacity energy storage to support personal electronics, newer devices such as unmanned aerial vehicles, as well as the commercialization of electric vehicles, ...current energy storage technologies are facing increased challenges. Although alternative batteries have been intensively investigated, lithium (Li) batteries are still recognized as the preferred energy storage solution for the consumer electronics markets and next generation automobiles. However, the commercialized Li batteries still have disadvantages, such as low capacities, potential safety issues, and unfavorable cycling life. Therefore, the design and development of electromaterials toward high‐energy‐density, long‐life‐span Li batteries with improved safety is a focus for researchers in the field of energy materials. Herein, recent advances in the development of novel organic electrolytes are summarized toward solid‐state Li batteries with higher energy density and improved safety. On the basis of new insights into ionic conduction and design principles of organic‐based solid‐state electrolytes, specific strategies toward developing these electrolytes for Li metal anodes, high‐energy‐density cathode materials (e.g., high voltage materials), as well as the optimization of cathode formulations are outlined. Finally, prospects for next generation solid‐state electrolytes are also proposed.
High‐energy‐density and safe solid‐state lithium batteries are vital to advance today's consumer electronic and automobile applications. The advances in electromaterials research at Deakin University are summarized, with a focus on alternative solid electrolyte designs, including organic ionic plastic crystals, novel polymer electrolytes, and high capacity cathodes.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Invited for this month's cover, the researchers from Huaqiao University and Jilin Jianzhu University. The Cover image shows the use of spent graphite to prepare hydrogels for photothermal evaporation ...to produce clean water. The Research Article itself is available at 10.1002/cssc.202300845.
“we can contribute highly to the goal of carbon neutrality through this promising green cycle…” This and more about the story behind the research that inspired the Cover image is presented in the Cover Profile. Read the full text of the corresponding research at 10.1002/cssc.202300845. View the Front Cover here: 10.1002/cssc.202301715.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
High‐performance rechargeable all‐solid‐state lithium metal batteries with high energy density and enhanced safety are attractive for applications like portable electronic devices and electric ...vehicles. Among the various solid electrolytes, argyrodite Li6PS5Cl with high ionic conductivity and easy processability is of great interest. However, the low interface compatibility between sulfide solid electrolytes and high capacity cathodes like nickel‐rich layered oxides requires many thorny issues to be resolved, such as the space charge layer (SCL) and interfacial reactions. In this work, in situ electrochemical impedance spectroscopy and in situ Raman spectroscopy measurements are performed to monitor the detailed interface evolutions in a LiNi0.8Co0.1Mn0.1O2 (NCM)/Li6PS5Cl/Li cell. Combining with ex situ characterizations including scanning electron microscopy and X‐ray photoelectron spectroscopy, the evolution of the SCL and the chemical bond vibration at NCM/Li6PS5Cl interface during the early cycles is elaborated. It is found that the Li+ ion migration, which varies with the potential change, is a very significant cause of these interface behaviors. For the long‐term cycling, the SCL, interfacial reactions, lithium dendrites, and chemo‐mechanical failure have an integrated effect on interfaces, further deteriorating the interfacial structure and electrochemical performance. This research provides a new insight on intra and intercycle interfacial evolution of solid‐state batteries.
Several in situ and ex situ measurements are used to monitor the interfacial evolutions in a LiNi0.8Co0.1Mn0.1O2 (NCM)/Li6PS5Cl/Li cell. The detailed interfacial evolution shows very different behavior between inter and intracycles. The evolution of the space charge layer and the chemical bond vibration at NCM/Li6PS5Cl interface play key roles during the early cycles.
Full text
Available for:
FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Large interfacial resistance resulting from interfacial reactions is widely acknowledged as one of the main challenges in sulfide electrolytes (SEs)‐based all‐solid‐state lithium batteries (ASSLBs). ...However, the root cause of the large interfacial resistance between the SEs and typical layered oxide cathodes is not fully understood yet. Here, it is shown that interfacial oxygen loss from single‐crystal LiNi0.5Mn0.3Co0.2O2 (SC‐NMC532) chemically oxidizes Li10GeP2S12, generating oxygen‐containing interfacial species. Meanwhile, the interfacial oxygen loss also induces a structural change of oxide cathodes (layered‐to‐rock salt). In addition, the high operation voltage can electrochemically oxidize SEs to form non‐oxygen species (e.g., polysulfides). These chemically and electrochemically oxidized species, together with the interfacial structural change, are responsible for the large interfacial resistance at the cathode interface. More importantly, the widely adopted interfacial coating strategy is effective in suppressing chemically oxidized oxygen‐containing species and mitigating the coincident interfacial structural change but is unable to prevent electrochemically induced non‐oxygen species. These findings provide a deeper insight into the large interfacial resistance between the typical SE and layered oxide cathodes, which may be of assistance for the rational interface design of SE‐based ASSLBs in the future.
Interfacial electrochemical and chemical reactions are analyzed in sulfide electrolyte (SE)‐based all‐solid‐state lithium batteries (ASSLBs). It is found that interfacial oxygen loss, coincident interfacial structural change, and electrochemical oxidation of SEs are responsible for the large interfacial resistance of SE‐based ASSLBs. The widely adopted interfacial coating is only effective in suppressing interfacial chemical reactions, but not electrochemical side reactions.
Full text
Available for:
FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Solid electrolytes are the most promising substitutes for liquid electrolytes to construct high‐safety and high‐energy‐density energy storage devices. Nevertheless, the poor lithium ion mobility and ...ionic conductivity at room temperature (RT) have seriously hindered their practical usage. Herein, single‐layer layered‐double‐hydroxide nanosheets (SLN) reinforced poly(vinylidene fluoride‐co‐hexafluoropropylene) (PVDF‐HFP) composite polymer electrolyte is designed, which delivers an exceptionally high ionic conductivity of 2.2 × 10−4 S cm−1 (25 °C), superior Li+ transfer number (≈0.78) and wide electrochemical window (≈4.9 V) with a low SLN loading (≈1 wt%). The Li symmetric cells demonstrate ultra‐long lifespan stable cycling over ≈900 h at 0.1 mA cm−2, RT. Moreover, the all‐solid‐state Li|LiFePO4 cells can run stably with a high capacity retention of 98.6% over 190 cycles at 0.1 C, RT. Moreover, using LiCoO2/LiNi0.8Co0.1Mn0.1O2, the all‐solid‐state lithium metal batteries also demonstrate excellent cycling at RT. Density functional theory calculations are performed to elucidate the working mechanism of SLN in the polymer matrix. This is the first report of all‐solid‐state lithium batteries working at RT with PVDF‐HFP based solid electrolyte, providing a novel strategy and significant step toward cost‐effective and scalable solid electrolytes for practical usage at RT.
Single‐layer layered‐double‐hydroxide nanosheets (SLN) reinforced poly(vinylidene fluoride‐co‐hexafluoropropylene) composite polymer electrolyte is originally designed, delivering an exceptional ionic conductivity of 2.2 × 10‐4 S cm‐1 at 25 °C with an ultra‐low SLN loading (≈1 wt%). Both the all‐solid‐state Li symmetric cells and half cells can cycle stably at room temperature with the robust solid electrolyte.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
The halide solid‐state electrolytes (SSEs) have received significant attention due to their high ionic conductivity and desirable compatibility with cathode materials. However, the reduction ...potential of the halide is still >0.6 V (versus Li/Li+). Reduction stability is still one of the challenges that need to be addressed. The fluorides have a wide electrochemical stability window due to the large electronegativity of F–. In contrast, Li3YBr6 (LYB) bromides have a narrower electrochemical window, although they have high lithium ion conductivity (>10–3 S cm–1). Herein, a fluorine doping strategy is employed. The interfacial stability between fluoride‐doped bromides and lithium metal is researched by cycling of lithium symmetric cells. Li plating/stripping can maintain over 1000 h at 0.75 mA cm–2. Interfacial protection mechanisms investigated by X‐ray photoelectron spectroscopy. A fluoride‐rich interfacial layer is formed in situ during the cycle, which achieves inhibition of the reduction. The Li metal treated fluorine doping of LYB exhibits significant potential in full cells. In fact, the induction of a stable in situ interfacial layer by fluorine doping can effectively improve the interfacial stability of bromides to lithium metal. Fluorine‐doped modification offers a new attempt to realize lithium metal applications in all‐solid‐state lithium batteries.
A fluoride‐rich interfacial layer is formed in situ during the cycle of an all‐solid‐state lithium battery, which achieves inhibition of unwanted reduction. The formation of in situ fluorinated layers in the cycling process enables higher contact areas and uniform distribution, which contributes to high cycle stability. The stable interfacial layer by fluorine doping can effectively improve the interfacial stability of bromides to lithium metal.
Full text
Available for:
FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Effective solid‐state interfacial contact of both the cathode and lithium metal anode with the solid electrolyte (SE) are required to improve the performance of solid‐state lithium metal batteries ...(SSBs). Electro–chemo–mechanical coupling (ECMC) strongly affects the interfacial stability of SSBs. On one hand, mechanical stress strongly influences interfacial contact and causes side reactions. On the other hand, electrochemical reactions such as lithium deposition cause mechanical deformation and stress at electrode/SE interfaces. To solve the degradation/failure problems of interfaces and provide guidelines to construct high‐performance SSBs, the ECMC at electrode/SE interfaces should be comprehensively investigated. In this review, the problems associated with ECMC at electrode/SE interfaces are summarized. The interfacial degradation/failure mechanisms, including the contact and electrochemical stability of interfaces, are introduced. Mechanical factors affecting interfacial contact and lithium deposition are highlighted. Experimental observation and computational analysis methods for electrode/SE interfaces are then summarized. Strategies to construct stable electrode/SE interfaces, such as assembling stress and wetting layers to improve interfacial contact, 3D SE structure, and plating stress relief to suppress lithium dendrite formation, are reviewed. The remaining challenges to better understanding ECMC and related solutions to aid SSB development are discussed.
The failure mechanisms of electrode/solid electrolyte (SE) interfaces in solid‐state lithium metal batteries (SSBs) involve multiscale and multiphysical field coupling. Various in situ observation technologies and corresponding theoretical approaches have been used to investigate the degradation mechanism of SSBs. Based on the experimental and theoretical results, well‐established solutions are explored to construct stable electrode/SE interfaces in SSBs.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
PDF
