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Solid electrolytes (SEs) with high conductivity and better stability against lithium metal are the most important requirements for successful commercialization of solid-state battery (SSB) technology. Therefore, in the search for new SEs with the above-mentioned qualities, halogen elements (Cl, Br, and I) were explored in an Li–P–S–O system to prepare Li10GeP2S12 (LGPS)-structured SEs. Among all the prepared SEs, Li3.3PS3.7O0.3Br0.1 and Li3.3PS3.7O0.3I0.1 compositions showed the highest conductivities of 0.77 mS cm−1 and 0.93 (≈1.0) mS cm−1, respectively, at 25 °C. These compounds also showed superior stability against lithium metal in symmetric and full SSB cells tested with an LiNi0.8Co0.15Al0.05O2 (NCA) cathode and graphite anode. Generally, the instability of sulfide-based SEs in an ambient environment is a major issue, whereas our prepared compounds Li3.3PS3.7O0.3Br0.1 and Li3.3PS3.7O0.3I0.1 showed 5 times higher stability under ambient environment conditions as compared to non-doped Li3.2PS3.7O0.3. In situ EIS study performed on the as-prepared full SSBs and after charge–discharge cycles revealed the contribution of interfacial reactions to impedance. Higher interfacial resistances in the full SSB with the Li-metal anode compared to those with the graphite anode were also revealed. The in situ EIS study confirmed that the Li3.3PS3.7O0.3I0.1 solid electrolyte formed the most stable interface with NCA, graphite and Li metal. Finally, postmortem analysis of the full SSB cell and an SE–Li interfacial study conducted using SEM and elemental mapping revealed morphological changes in the electrodes and electrolytes before and after charge–discharge cycles. In summary, the present work reports new sulfide-based solid electrolytes with high conductivity, better air/moisture stability, and excellent interfacial stability. [ABSTRACT FROM AUTHOR]

A new layered titanoniobate, Li3Ti5NbO14, a member of the AxM2nO4n+2 family, has been synthesized using a molten salt reaction between H3Ti5NbO14 and an eutectic mixture of LiOH and LiNO3. This compound crystallizes in the P21/m space group with a = 9.273(15) Å, b = 3.788(6) Å, c = 8.871(3) Å, and β = 114.33(1)°, as determined by 3D electron diffraction single crystal analysis. It exhibits [Ti5NbO14]3− layers similar to K3Ti5NbO14, but differs from the latter by a 'parallel configuration' of its [Ti5NbO5]3− ribbons between the two successive layers. The topotactic character of the reaction suggests that exfoliation plays a prominent role in the synthesis of this new form. This new phase intercalates reversibly 2 lithium through a first-order transformation leading to a capacity of 100 mA h g−1 at a potential of 1.67 V vs. Li/Li+. [ABSTRACT FROM AUTHOR]

Lithium-ion batteries are nowadays a mature technology for energy storage. However, some safety problems have been identified during their operation in high power applications such as fire incidents in electric vehicles. The most promising solution to improve the safety of lithium-ion batteries is replacing the current organic liquid based electrolytes with solid electrolytes. In this context, new solid electrolytes having chemical and electrochemical stability with high ionic conductivity need to be discovered. Therefore, in the present study, a new LGPS-type structural domain is highlighted for the Li–B–P–S system. Ionic conductivities of up to 10−4 S cm−1 have been achieved for prepared solid electrolytes in the Li–B–P–S system, and higher stability against lithium metal as compared to Li10GeP2S12. These solid electrolytes also show better electrochemical characteristics in all solid-state batteries. [ABSTRACT FROM AUTHOR]

Disordered rock salt (DRS) cathodes have attracted considerable attention because of their high first charge capacities and relatively low cost. Here we investigate operando the structure and charge evolution of the Li1.1Mn0.7Ti0.2O2 Li-excess rock salt cathode with a first charge capacity of 270 mA h g−1. We associate a certain extent of the capacity fade in DRS to the in situ formation of locally ordered layered nanodomains during the electrochemical cycling of the long-range cation disordered rock salt. We quantify the short-range ordering of cations during cycling and evaluate its effect on the lithium-ion diffusion and charge compensation using operando studies based on X-ray total scattering and advanced spectroscopic methods at the Mn K-edge, namely high energy resolution fluorescence detected XANES and emission spectroscopies including main and valence-to-core transitions. [ABSTRACT FROM AUTHOR]

The full structure of nano-Li2MnO3 with superior reversible capacities of 290 mA h g−1 for over 10 cycles was investigated by neutron and X-ray total scattering, which demonstrate that contrary to previous claims, a phase transformation occurs during synthesis forming a disordered cubic MnO-type rock-salt with nanodomains of Li/Mn layering of ∼1 nm. A comprehensive study of the structural and charge evolution combining in operando X-ray total scattering with advanced spectroscopic methods at the Mn K-edge such as High Energy Resolved Fluorescence Detected XANES, EXAFS and Emission Spectroscopies including main and valence-to-core transitions, point to a lattice densification with an effective loss of Li2O, with the subsequent electrochemical activation of Li2O as the main responsible mechanism for the exchanged capacity. Interestingly, and unlike previous studies, no capacity losses could be associated to the material's densification. [ABSTRACT FROM AUTHOR]

The irreversible loss of lithium from the cathode material during the first cycles of rechargeable Li‐ion batteries notably reduces the overall cell capacity. Here, a new family of sacrificial cathode additives based on Li2O:Li2/3Mn1/3O5/6 composites synthesized by mechanochemical alloying is reported. These nanocomposites display record (but irreversible) capacities within the Li–Mn–O systems studied, of up to 1157 mAh g−1, which represents an increase of over 300% of the originally reported capacity in Li2/3Mn1/3O5/6 disordered rock salts. Such a high irreversible capacity is achieved by the reaction between Li2O and Li2/3Mn1/3O5/6 during the first charge, where electrochemically active Li2O acts as a Li+ donor. A 13% increase of the LiFePO4 and LiCoO2 first charge gravimetric capacities is demonstrated by the addition of only 2 wt% of the nanosized composite in the cathode mixture. This result shows the great potential of these newly discovered sacrificial additives to counteract initial losses of Li+ ions and improve battery performance. [ABSTRACT FROM AUTHOR]

A copper hydroxydiphosphate, Cu(sub 3)[P2O6OH](sub 2), was synthesized by soft chemistry and structurally characterized. Magnetization measurements confirm the presence of divalent copper and suggest antiferromagnetic interactions at low temperature.