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High Li+ transference number electrolytes have long been understood to provide attractive candidates for realizing uniform deposition of Li+. However, such electrolytes with immobilized anions would result in incomplete solid electrolyte interphase (SEI) formation on the Li anode because it suffers from the absence of appropriate inorganic components entirely derived from anions decomposition. Herein, a boron‐rich hexagonal polymer structured all‐solid‐state polymer electrolyte (BSPE+10% LiBOB) with regulated intermolecular interaction is proposed to trade off a high Li+ transference number against stable SEI properties. The Li+ transference number of the as‐prepared electrolyte is increased from 0.23 to 0.83 owing to the boron‐rich cross‐linker (BC) addition. More intriguingly, for the first time, the experiments combined with theoretical calculation results reveal that BOB− anions have stronger interaction with B atoms in polymer chain than TFSI−, which significantly induce the TFSI− decomposition and consequently increase the amount of LiF and Li3N in the SEI layer. Eventually, a LiFePO4|BSPE+10% LiBOB|Li cell retains 96.7% after 400 cycles while the cell without BC‐resisted electrolyte only retains 40.8%. BSPE+10% LiBOB also facilitates stable electrochemical cycling of solid‐state Li‐S cells. This study blazes a new trail in controlling the Li+ transport ability and SEI properties, synergistically. [ABSTRACT FROM AUTHOR]

Garnet Li7La3Zr2O12 (LLZO) is regarded as a promising solid electrolyte due to its high Li+ conductivity and excellent chemical stability, but suffers from grain boundary resistance and porous structure which restrict its practical applications in lithium–metal batteries. Herein, a novel and highly efficient TiO2‐induced conversion strategy is proposed to generate Li ion‐conductive Li0.5La0.5TiO3, which can simultaneously eliminate the pre‐existing pores/voids and contamination Li2CO3. The Li/LLZTO‐5TiO2/Li symmetric cell exhibits a high critical current density of 1.1 mA cm−2 at 25°C, and the long‐term lithium cycling stability of over 1500 h at 0.1 mA cm−2. More importantly, the excellent performance of LLZTO‐5TiO2 electrolyte is verified by LiCoO2/LiFePO4 coupled full cells. For example, The LiCoO2 coupled full cell exhibits a significant discharge rate capacity of 108 mAh g−1 at 0.1 C, and a discharge capacity retention rate of 91.23% even after 150 cycles of charge and discharge. COMSOL Multiphysics and density functional theory calculation reveal that LLZTO‐5TiO2 electrolyte has a strong lithium affinity and uniform Li ions distribution, which can improve the cycle stability of Li–metal batteries by preventing dendrite growth. [ABSTRACT FROM AUTHOR]

Polyester‐based electrolytes formed via in situ polymerization, have been regarded as one of the most promising solid electrolyte systems. Nevertheless, it is still a great challenge to address the issue of their high reactivity with metallic lithium anode by optimizing the components and properties of solid electrolyte interphase (SEI). Herein, a new class of N‐containing additive, isopropyl nitrate (ISPN) that can be miscible with ester solvents is demonstrated, and a chemically stable and ion‐conductive LiF‐Li3N composite SEI is constructed. In addition, ISPN can induce the formation of anion‐enriched solvation structures and reduces the desolvation barrier of Li+, resulting in fast transport of Li+. With the addition of ISPN, ionic conductivity of the electrolyte has nearly doubled, reaching as high as 5.3 × 10−4 S cm−1. What's more, the LiFePO4 (LFP)|ISPN‐PTA|Li cell exhibits exceptional cycle stability and fast charging capabilities, maintaining stable cycling for 850 cycles at 10 C rate. Even when paired with the high‐voltage cathode, the LiNi0.6Co0.2Mn0.2O2 (NCM622)|ISPN‐PTA|Li cell achieves an impressive capacity retention of 97.59% after 165 cycles at 5 C. This study offers a novel approach for ester‐based polymer electrolytes, paving the way toward the development of stable and high‐energy Li metal battery technologies. [ABSTRACT FROM AUTHOR]

[Display omitted] • A concept of multifunctional Li+ traffic controller is proposed. • The traffic controller can effectively regulate the distribution of Li+. • The traffic controller stabilizes the electrode-electrolyte interface. • The traffic controller layer enables ultra-low N/P ratio full cells. The performance of thin lithium metal anodes is affected due to issues that weaken the electrode-electrolyte interphase. In this work, a coating layer serving as a Li+ traffic controller based on hexadecyl trimethyl ammonium bis(trifluoromethanesulphonyl)imide ([CTA][TFSI]) and poly (vinylidene difluoride co-hexafluoropropylene) (P(VDF-HFP)) is used to stabilize the thin lithium metal interface. The CTA+ ions in the coating layer can effectively regulate the distribution of Li+ concentration to promote uniform deposition of lithium. The anion of [CTA][TFSI] can optimize solid electrolyte interphase (SEI) with inorganic-rich components, which improve the ionic conductivity and reaction kinetics. Furthermore, the flexible polymer skeleton can fortify the fragile SEI, facilitating the consistent operation of the battery. Due to these improvements, a thin Li metal anode (4 mAh cm−2) with a coating layer in a Li||Li symmetric cell demonstrates a lifespan of 600 h at 1 mA cm−2 and 1 mAh cm−2. Notably, full cells with an ultra-low negative electrode/positive electrode = 1 (N/P = 1) demonstrate a stable performance over 200 cycles and 90 cycles at 0.5C and 1C (1C = 170 mA g−1), respectively. [ABSTRACT FROM AUTHOR]

[Display omitted] Solid-state polymer electrolytes are outstanding candidates for next-generation lithium metal batteries in the realm of high specific energy densities, high safeties and tight contact with electrodes. However, their applications are still hindered by the limitations that no single polymer is electrochemically stable with the oxidizing high-voltage cathode and the highly reductive Li anode, simultaneously. Herein, a bilayer asymmetric polymer electrolyte (SL-SPE) without accessional interface resistance that using poly (ethylene glycol) diacrylate (PEGDA) as a "bridge" to connect the sulfonyl (O S = O)-contained oxidation-tolerated layer and polyether-derived reduction-tolerated layer (SPE), is proposed and synthesized by sequential two-step UV polymerizations. SL-SPE can provide widened electrochemical stability window up to 5 V, while simultaneously deploying a stable Janus interface property. Eventually, the superior high-voltage (4.4 V) cycling durability can be displayed in LiNi 0.6 Co 0.2 Mn 0.2 O 2 |SL-SPE|Li batteries. This finding provides a bran-new idea for designing multifunctional polymer electrolytes in the application of solid-state batteries. [ABSTRACT FROM AUTHOR]

Lithium–sulfur batteries have sparked a lot of interests because of their high specific capacity and low cost. However, due to the 'shuttle effect', unstable Li metal and side reactions, the performance of LSBs is less than expected. Herein, we design a localized high-concentration electrolyte (LHCE), using carbonate as the base solvent, hexafluoroisopropyl methyl ether (HFME) as the diluent, and vinylene carbonate (VC) as the filmogen to realize a stable solid-solid cyclic process in LSBs. For the cathode side, carbonate solvent molecules with Li+-coordination can reduce the nucleophilic side reactivity with lithium sulfide. The initial surface reaction between VC and lithium sulfide forms an effective cathode electrolyte interface (CEI), which can continuously protect the cathode active substances and realize a stable solid-solid conversion process. For the anode side of lithium metal, in combination with Li+-coordinated TFSI− in LHCE, a stable solid electrolyte interface (SEI) can be formed by VC on Li anode which improves the stability of Li anode. As a result, the cyclic performance of LSBs is significantly improved, demonstrating a high specific capacity and stability. Furthermore, the self-discharge is nearly stopped. This work provides a universal strategy to design new electrolytes to improve Li–S battery performance. [Display omitted] • A localized high-concentration carbonate electrolyte for Li–S batteries is designed. • Simple strategy to simultaneously synthesize CEI and SEI films. • Elimination of side reactions between sulfur cathode and carbonate solvents. [ABSTRACT FROM AUTHOR]