Although solid-state Li-metal batteries (LMBs) featuring polymer-based solid electrolytes might one day replace conventional Li-ion batteries, the poor Li-ion conductivity of solid polymer electrolytes at low temperatures has hindered their practical applications. Herein, we describe the first example of using a co-precipitation method in a Taylor flow reactor to produce the metal hydroxides of both the Ga/F dual-doped Li7La3Zr2O12 (Ga/F-LLZO) ceramic electrolyte precursors and the Li2MoO4-modified Ni0.8Co0.1Mn0.1O2 (LMO@T-LNCM 811) cathode materials for LMBs. The Li/Nafion (LiNf)-coated Ga/F-LLZO (LiNf@Ga/F-LLZO) ceramic filler was finely dispersed in the poly­(vinylidene fluoride)/polyacrylonitrile/lithium bis­(trifluoromethanesulfonimide)/succinonitrile matrix to give a trilayer composite polymer electrolyte (denoted “Tri-CPE”) through a simple solution-casting. The bulk ionic conductivity of the Tri-CPE at room temperature was approximately 4.50 × 10–4 S cm–1 and exhibited a high Li+ ion transference number (0.84). It also exhibits a broader electrochemical window of 1–5.04 V versus Li/Li+. A full cell based on a CR2032 coin cell containing the LMO@T-LNCM811-based composite cathode, when cycled under 1 C/1 C at room temperature for 300 cycles, achieved an average Columbic efficiency of 99.4% and a capacity retention of 89.8%. This novel fabrication strategy for Tri-CPE structures has potential applications in the preparation of highly safe high-voltage cathodes for solid-state LMBs.

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In this study, we synthesized a Li-containing "BTJ-L" hybrid oligomerobtained through polymerization of bismaleimide (BMI) with a polyether monoamine (i.e., Jeffamine-M1000, JA), trithiocyanuric acid (TCA), and LiOHand coated it as an additive in various amounts (0.5−2 wt %) onto the surface of a Ni-rich LiNi 0.8 Co 0.1 Mn 0.1 O 2 (NCM811) cathode active material, forming BTJ-L@NCM811 electrodes for lithiumion batteries (LIBs). Relative to CR2032 coin-type cells incorporating a pristine NCM811 electrode, the cells with the 1 wt % BTJ-L@NCM811 electrode demonstrated a slightly higher initial discharge capacity (173 mAh g −1 vs171 mAh g −1 ) and higher values of average Coulombic efficiency, CE avg (99.5% vs98.9%) and capacity retention, CR (86.1% vs72.9%) after 100 cycles at 1C. Electrochemical impedance spectroscopy revealed that the decrease in the charge transfer resistance (R ct : 46.7 Ω vs171.1 Ω) and the superior Li + ion diffusivity (D Li + : ∼1.09 × 10 −12 cm 2 s −1 vs ∼1.61 × 10 −13 cm 2 s −1 ) of the cells incorporating the BTJ-L@NCM811 electrode after cycling at 1C could be attributed to the excellent wettability toward the electrolyte and the extra Li + ions contributed by the hybrid BTJ-L oligomer additive. Therefore, the BTJ-L oligomer coating layer functioned much like an artificial cathode electrolyte interphase (CEI) layer, impairing the dissolution of transition metals (TMs) from the cathode materials into the carbonate-based electrolytes. Furthermore, in situ microcalorimetry manifested that the total exothermic heat generation (Q t ) of the coin cells containing the 1 wt % BTJ-L@NCM811 electrode operating at 1C in isothermal modes (35 and 55 °C) during the charging process was dramatically lower (by ca. 45%) relative to that of the cells incorporating the pristine NCM811 electrode. On the basis of an ARC-HWS analysis, the delithiated pristine NCM811 electrode shows thermal reactivity with the electrolyte at a much earlier stage in comparison to the 1 wt % BTJ-L@NCM811 counterpart (843 min vs 1039 min) between 171 and 192 °C. Thus, Ni-rich NCM811 cathode materials coated with trace amounts (i.e., 1 wt %) of the BTJ211-L1 hybrid oligomer additives displayed both enhanced electrochemical performance and remarkably improved thermal stability. Accordingly, this Li-containing BTJ-L hybrid oligomer appears to be a great candidate material for coating high-Ni oxide cathode materials to enhance the safety and electrochemical performance of LIB cells.

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Safety is an extremely important factor when developing Li metal anodes for high-energy-density battery systems. Lithium dendrite formation is one of the major phenomena leading to serious safety issues and poor lifetimes of lithium batteries. In this study, we applied a combined surface modification strategy to obtain stable dendrite-free Li anodes for solid-state lithium batteries (SSLBs). We coated a polydopamine (PDA)-functionalized vapor-grown carbon nanofiber (VGCF)/ lithiated-Nafion (LiNf) polymer composite (VGCF@PDA/LiNf) as a protective layer onto a patterned Li metal surface to provide selective lithiophilic sites for Li deposition. We also applied a sandwich-type hybrid solid polymer electrolyte (HSE) membrane