ABSTRACT
Lithium-sulfur batteries (LSBs) take a leading stand in developing next-generation secondary batteries with an exceptionally high theoretical energy density. However, the insulating nature and undesirable shuttle effect still need to be solved to improve the electrochemical performance. Herein, a freestanding graphene supported N-doped Ti3C2T x MXene@S cathode is successfully synthesized via a straightforward no-slurry method. Due to its unique hierarchical microstructure, the MXene-C/S ternary hybrids with high capacity can effectively adsorb polysulfides and accelerate their conversion. Cooperatively, conductive rGO can ameliorate N-MXene nanosheet' restacking, making the lamellar N-Mxene coated sulfur particles disperse uniformly. The assembled Li-S battery with a freestanding Ti3C2T x @S/graphene electrode provides an initial capacity of 1342.6 mA h g-1 at 0.1C and only experiences a low capacity decay rate of 0.067% per cycle after. Even at a relatively high loading amount of 5 mg cm-2, the battery can still yield a high specific capacity of 684.9 mA h g-1 at 0.2C, and a capacity retention of 89.3% after 200 cycles.
ABSTRACT
Objective To use cyclic amplified fluorescence immunoassay method and electrochemiluminescence immunoassay method for quantitative detection of procalcitonin (PCT),and to evaluate the consistency of the test results.Methods With the method of electrochemiluminescence used as the contrast method and the cyclic enhanced fluorescence immunoassay method used as experimental method,samples of 219 hospitalized patients were measured in two ways.The results were divided into three groups:the serum group (Core serum group) and the micro blood group (Core micro blood group) which were detected in cyclic amplified fluorescence immunoassay method and the serum group (Roche serum group) which was detected by electrochemiluminescence immunoassay method.The data of three groups were compared with each other in paired t test,and correlation analysis,the relative sensitivity,the relative specificity,and Jorden index at the medical decision level (0.5 ng/mL and 2.0 ng/mL) were calculated and the Kappa Consistency Test was calculated.Results There were no statistical differences in three groups (P＞0.05).The Core serum group was positively correlated with the Roche serum group (r =0.993,P＜0.01).The linear regression equation was Y =-0.061+1.041X(0.04≤X≤60).The Core micro blood group was positively correlated with the Roche serum group(r=0.989,P＜0.01).The linear regression equation was Y=0.022+1.023X(0.04≤X≤60).The Core micro blood group was positively correlated with the Core serum group (r=0.986,P＜0.01).The linear regression equation was Y=0.129+0.973X(0.04≤X≤60).The relative sensitivity of the three comparison groups was greater than 92％ and the relative specificity was greater than 95％ at the medical decision level (0.5 ng/mL and 2.0 ng/mL),and the Jorden index and Kappa values were greater than 0.9.It indicated a better consistency.Conclusion Cyclic amplified fluorescence immunoassay and electrochemiluminescence immunoassay detection results were very consistent,which meet the clinical testing requirements.