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Co shows excellent performance in the high voltage range for layered oxide cathode materials for sodium ion batteries (SIBs). However, its high cost and toxicity are significant disadvantages.Co‐free cathodes with high performance are urgently needed for development. Herein, cheap Mg and Ti elements are preferred to replace Co elements. A P2‐Na0.67Mn0.53Ni0.30Mg0.085Ti0.085O2 (Ni30MgTi) cathode shows a high reversible specific capacity of 118 mA h g−1 at a current density of 50 mA g−1 in 2.0–4.25 V, which is even higher than that in the base sample with Co. Moreover, Mg and Ti raise the median discharge voltage from 3.21 to 3.59 V, which raises the energy density from 325 to 410 Wh kg−1. On the other hand, ex situ XPS and in situ differential electrochemical mass spectrometry tests indicate that Ni30MgTi has a stable anionic redox reaction with reversible capacity in the high voltage range. The concept of bimetallic co‐substitution offers a simple and effective Co‐free strategy to reduce the cost and increase the energy density of layered oxide cathode materials simultaneously for SIBs. [ABSTRACT FROM AUTHOR]

LiNi x Co y Mn 1-x-y O 2 (NCM, x ≥ 0.6) possessing a high nickel content is a favorable cathode candidate for next-generation lithium-ion batteries (LIBs) owing to its ultra-high energy density. However, its sluggish electrochemical kinetics at low temperatures and severe structure destruction at high temperatures limit its practical application. This study presents a facile surface modification strategy based on niobium (Nb) to achieve LiNbO 3 coating and Nb5+ doping, which can address both problems under extreme temperatures (-30-50 °C). More specifically, the LiNbO 3 coating layer can decrease polarization and charge transfer resistance and enhance the structural stability of nickel-rich NCM (LiNi 0·83 Co 0·12 Mn 0·05 O 2); Nb5+ dopants can widen the lithium-ion migration channels and thus improve the diffusion kinetics. The Nb-modified NCM (Nb-NCM) exhibits a high discharge specific capacity at subzero temperatures and excellent stability throughout the temperature range. To further evaluate the practical application potential of the Nb-NCM electrode, full cells are fabricated and tested using the Nb-NCM as a cathode and Li 4 Ti 5 O 12 (LTO) as an anode. Encouragingly, the full cell also shows excellent electrochemical performance between −30 and 50 °C. These findings provide a facile and scalable strategy to enhance the electrochemical performance of nickel-rich NCM across a broad temperature range. • Designing a facile Nb-modification strategy including Nb doping and LiNbO 3 doping. • Nb-NCM shows excellent performance between wide temperature ranges. • Nb-modification improves the structure stability of the high-nickel NCM. • Nb-NCM also shows better electrochemical kinetics. [ABSTRACT FROM AUTHOR]

Solid‐state lithium metal batteries (SLMBs) are attracting enormous attention due to their enhanced safety and high theoretical energy density. However, the alkali lithium with high reducibility can react with the solid‐state electrolytes resulting in the inferior cycle lifespan. Herein, inspired by the idea of interface design, the 1‐butyl‐1‐methylpyrrolidinium bis(trifluoromethanesulfonyl) imide as an initiator to generate an artificial protective layer in polymer electrolyte is selected. Time‐of‐flight secondary ion mass spectrometry and X‐ray photoelectron spectroscopy reveal the stable solid electrolyte interface (SEI) is in situ formed between the electrolyte/Li interface. Scanning electron microscopy (SEM) images demonstrate that the constructed SEI can promote homogeneous Li deposition. As a result, the Li/Li symmetrical cells enable stable cycle ultralong‐term for over 4500 h. Moreover, the as‐prepared LiFePO4/Li SLMBs exhibit an impressive ultra‐long cycle lifespan over 1300 cycles at 1 C, as well as 1600 cycles at 0.5 C with a capacity retention ratio over 80%. This work offers an effective strategy for the construction of the stable electrolyte/Li interface, paving the way for the rapid development of long lifespan SLMBs. [ABSTRACT FROM AUTHOR]

For the past few years, a new generation of energy storage systems with large theoretical specific capacity has been urgently needed because of the rapid development of society. Lithium–sulfur (Li−S) batteries are regarded as one of the most promising candidates for novel battery systems, since their resurgence at the end of the 20th century Li−S batteries have attracted ever more attention, attributed to their notably high theoretical energy density of 2600 W h kg−1, which is almost five times larger than that of commercial lithium‐ion batteries (LIBs). One of the determining factors in Li−S batteries is how to design/prepare the sulfur cathode. For the sulfur host, the major technical challenge is avoiding the shuttling effect that is caused by soluble polysulfides during the reaction. In past decades, though the sulfur cathode has developed greatly, there are still some enormous challenges to be conquered, such as low utilization of S, rapid decay of capacity, and poor cycle life. This article spotlights the recent progress and foremost findings in improving the performance of Li−S batteries by employing multifunctional metal phosphides as host materials. The current state of development of the sulfur electrode of Li−S batteries is summarized by emphasizing the relationship between the essential properties of metal phosphide‐based hybrid nanomaterials, the chemical reaction with lithium polysulfides and the latter′s influence on electrochemical performance. Finally, trends in the development and practical application of Li−S batteries are also pointed out. [ABSTRACT FROM AUTHOR]

Conventional lithium‐ion batteries, with flammable organic liquid electrolytes, have serious safety problems, which greatly limit their application. All‐solid‐state batteries (ASSBs) have received extensive attention from large‐scale energy‐storage fields, such as electric vehicles (EVs) and intelligent power grids, due to their benefits in safety, energy density, and thermostability. As the key component of ASSBs, solid electrolytes determine the properties of ASSBs. In past decades, various kinds of solid electrolytes, such as polymers and inorganic electrolytes, have been explored. Among these candidates, organic–inorganic composite solid electrolytes (CSEs) that integrate the advantages of these two different electrolytes have been regarded as promising electrolytes for high‐performance ASSBs, and extensive studies have been carried out. Herein, recent progress in organic–inorganic CSEs is summarized in terms of the inorganic component, electrochemical performance, effects of the inorganic ceramic nanostructure, and ionic conducting mechanism. Finally, the main challenges and perspectives of organic–inorganic CSEs are highlighted for future development. [ABSTRACT FROM AUTHOR]

The cathode, a crucial constituent part of Li-ion batteries, determines the output voltage and integral energy density of batteries to a great extent. Among them, Ni-rich LiNixCoyMnzO2 (x + y + z = 1, x ≥ 0.6) layered transition metal oxides possess a higher capacity and lower cost as compared to LiCoO2, which have stimulated widespread interests. However, the wide application of Ni-rich cathodes is seriously hampered by their poor diffusion dynamics and severe voltage drops. To moderate these problems, a nanobrick Ni-rich layered LiNi0.6Co0.2Mn0.2O2 cathode with a preferred orientation (110) facet was designed and successfully synthesized via a modified co-precipitation route. The galvanostatic intermittent titration technique (GITT) and electrochemical impedance spectroscopy (EIS) analysis of LiNi0.6Co0.2Mn0.2O2 reveal its superior kinetic performance endowing outstanding rate performance and long-term cycle stability, especially the voltage drop being as small as 67.7 mV at a current density of 0.5 C for 200 cycles. Due to its unique architecture, dramatically shortened ion/electron diffusion distance, and more unimpeded Li-ion transmission pathways, the current nanostructured LiNi0.6Co0.2Mn0.2O2 cathode enhances the Li-ion diffusion dynamics and suppresses the voltage drop, thus resulting in superior electrochemical performance. [ABSTRACT FROM AUTHOR]

Lithium–sulfur batteries (LSBs) have attracted much attention in the field of electrochemical energy storage due to their high energy density and low cost. However, the 'shuttle effect' of sulfur cathode, resulting in the poor cyclic performance of batteries, is a big barrier for the development of LSBs. To overcome this critical drawback, herein, a matrix of well-designed double carbon shells-encapsulated metallic Mo 2 C nanoparticles (Mo 2 C/C@C) is facilely achieved as an efficient sulfur host for high-performance LSBs. During the electrochemical process, the embedded polar and metallic Mo 2 C nanoparticles could effectively retard polysulfide migration. While for the carbon layers, they can not only act as conductive matrix but also promote the restriction for all sulfur species and maintain the structural stability simultaneously. Specially, the inner carbon layer is mainly for encapsulation and the outside one for surface-modification. As a result, such well-designed Mo 2 C/C@C–S cathode could effectively adsorb soluble polysulfides both from chemical and physical aspects, and well confines them inside the porous structure of Mo 2 C/C@C, thus achieving a high reversible capacity and superior cycling performance. Double carbon shells embedded with metallic and polar Mo 2 C nanoparticles (Mo 2 C/C@C) have been synthesized as efficient sulfur host materials for Li–S batteries. The obtained robust host materials greatly enhance the conductive of the electroactive sulfur and confine polysulfides to mitigate their dissolution effectively as well. Image 1 [ABSTRACT FROM AUTHOR]