Lithium
metal batteries are being explored in meeting ever-increasing energy
density needs. Because of serious dendritic lithium issues in liquid-state
electrolytes, it is generally thought that solid-state electrolytes
are potential alternatives for lithium metal batteries. Herein, we
design a new single lithium-ion conducting lithium poly[(cyano)(4-styrenesulfonyl)imide]
(LiPCSI) to replace the conventional dual-ion conducting salt for
use in solid polymer electrolytes (SPEs) that successfully suppress
the growth of lithium dendrites. Owing to highly delocalized anion
moiety and oxidation-resistant cyano group, the tailored PEO8–LiPCSI SPE exhibits extremely high Li+ transference
number (0.84) as well as oxidation potential (5.53 V vs Li+/Li). The symmetric Li/PEO8–LiPCSI/Li cell runs
for 1000 h at 60 °C without a short circuit. The rechargeable
solid-state Li/PEO8–LiPCSI/LiFePO4 cell
discharges a capacity of 141 mAh g–1 with retention
over 85% during 80 cycles. These merits enable the proposed PEO8–LiPCSI SPE to be very promising for solid-state lithium
metal battery applications.
The hybrid P3/P2-structured Na 0.5 Ni 0.3 Mn 0.7 O 2 as a cathode material for sodium-ion batteries (SIBs) demonstrates high initial discharge capacity. However, the existence of an unstable P3 phase leads to a fast capacity fade that is adverse to engineering applications. Herein, the introduction of inactive magnesium to partially replace electrochemically active nickel of Na 0.5 Ni 0.3 Mn 0.7 O 2 is proposed to reinforce the structural stability of the material. It is found that magnesium incorporation can suppress the growth of the P3 phase, and proper substitution of magnesium for nickel can even harvest pure P2 phase material. The X-ray diffraction (XRD) pattern reveals that the prepared Na 0.5 Ni 0.2 Mg 0.1 Mn 0.7 O 2 (Mg-0.1) is a structure-stable P2-type material. The fabricated Na 0.5 Ni 0.2 Mg 0.1 Mn 0.7 O 2 SIB cathode exhibits acceptable initial discharge capacity, tunable rate capability, and satisfactory cycling stability. These superior electrochemical properties account for low electrochemical resistances, fast Na + diffusion kinetics, and the extremely stable structure of the P2-Na 0.5 Ni 0.2 Mg 0.1 Mn 0.7 O 2 material, which are revealed by means of electrochemical impedance spectra and ex situ XRD technologies.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.