Indolocarbazole-Based Small Molecule Cathode-Active Material Exhibiting Double Redox for High-Voltage Li-Organic Batteries

Most organic electrode materials(OEMs)for rechargeable batteries employ n-type redox centers,whose redox potentials are intrinsically limited<3.0 V versus Li^(+)/Li.However,p-type materials possessing high redox potentials experience low specific capacities because they are capable of only a single redox reaction within the stable electrochemical window of typical electrolytes.Herein,we report 5,11-diethyl-5,11-dihydroindolo[3,2-b]carbazole(DEICZ)as a novel p-type OEM,exhibiting stable plateaus at high discharge potentials of 3.44 and 4.09 V versus Li^(+)/Li.Notably,the second redox potential of DEICZ is within the stable electrochemical window.The mechanism of the double redox reaction is investigated using both theoretical calculations and experimental measurements,including density functional theory calculations,ex situ electron spin resonance,and X-ray photoelectron spectroscopy.Finally,hybridization with single-walled carbon nanotubes(SWCNT)improves the cycle stability and rate performance of DEICZ owing to theπ-πinteractions between the SWCNT and co-planar molecular structure of DEICZ,preventing the dissolution of active materials into the electrolyte.The DEICZ/SWCNT composite electrode maintains 70.4%of its initial specific capacity at 1-C rate and also exhibits high-rate capability,even performing well at 100-C rate.Furthermore,we demonstrate its potential for flexible batteries after applying 1000 bending stresses to the composite electrode.

Antibiofilm and antithrombotic hydrogel coating based on superhydrophilic zwitterionic carboxymethyl chitosan for blood-contacting devices

Blood-contacting devices must be designed to minimize the risk of bloodstream-associated infections,thrombosis,and intimal lesions caused by surface friction.However,achieving effective prevention of both bloodstream-associated infections and thrombosis poses a challenge due to the conflicting nature of antibacterial and antithrombotic activities,specifically regarding electrostatic interactions.This study introduced a novel biocompatible hydrogel of sodium alginate and zwitterionic carboxymethyl chitosan(ZW@CMC)with antibacterial and antithrombotic activities for use in catheters.The ZW@CMC hydrogel demonstrates a superhydrophilic surface and good hygroscopic properties,which facilitate the formation of a stable hydration layer with low friction.The zwitterionic-functionalized CMC incorporates an additional negative sulfone group and increased negative charge density in the carboxyl group.This augmentation enhances electrostatic repulsion and facilitates the formation of hydration layer.This leads to exceptional prevention of blood clotting factor adhesion and inhibition of biofilm formation.Subsequently,the ZW@CMC hydrogel exhibited biocompatibility with tests of in vitro cytotoxicity,hemolysis,and catheter friction.Furthermore,in vivo tests of antithrombotic and systemic inflammation models with catheterization indicated that ZW@CMC has significant advantages for practical applications in cardiovascular-related and sepsis treatment.This study opens a new avenue for the development of chitosan-based multifunctional hydrogel for applications in blood-contacting devices.