Constructing globally consecutive 3D conductive network using P-doped biochar cotton fiber for superior performance of silicon-based anodes

The inferior conductivity and drastic volume expansion of silicon still remain the bottleneck in achieving high energy density Lithium-ion Batteries(LIBs).The design of the three-dimensional structure of electrodes by compositing silicon and carbon materials has been employed to tackle the above challenges,however,the exorbitant costs and the uncertainty of the conductive structure persist,leaving ample room for improvement.Herein,silicon nanoparticles were innovatively composited with eco-friendly biochar sourced from cotton to fabricate a 3D globally consecutive conductive network.The network serves a dual purpose:enhancing overall electrode conductivity and serving as a scaffold to maintain electrode integrity.The conductivity of the network was further augmented by introducing P-doping at the optimum doping temperature of 350℃.Unlike the local conductive sites formed by the mere mixing of silicon and conductive agents,the consecutive network can affirm the improvement of the conductivity at a macro level.Moreover,first-principle calculations further validated that the rapid diffusion of Li^(+)is attributed to the tailored electronic microstructure and charge rearrangement of the fiber.The prepared consecutive conductive Si@P-doped carbonized cotton fiber anode outperforms the inconsecutive Si@Graphite anode in both cycling performance(capacity retention of 1777.15 mAh g^(-1) vs.682.56 mAh g^(-1) after 150 cycles at 0.3 C)and rate performance(1244.24 mAh g^(-1) vs.370.28 mAh g^(-1) at 2.0 C).The findings of this study may open up new avenues for the development of globally interconnected conductive networks in Si-based anodes,thereby enabling the fabrication of high-performance LIBs.

Development of pretreatment protocol for DNA extraction from biofilm attached to biologic activated carbon(BAC)granules

The biologic activated carbon(BAC)process is widely used in drinking water treatments.A comprehensive molecular analysis of the microbial community structure provides very helpful data to improve the reactor performance.However,the bottleneck of deoxyribonucleic acid(DNA)extraction from BAC attached biofilm has to be solved since the conventional procedure was unsuccessful due to firm biomass attachment and adsorption capacity of the BAC granules.In this study,five pretreatments were compared,and adding skim milk followed by ultrasonic vibration was proven to be the optimal choice.This protocol was further tested using the vertical BAC samples from the full-scale biofilter of Pinghu Water Plant.The results showed the DNAyielded a range of 40μg·g^(-1) BAC(dry weight)to over 100μg·g^(-1) BAC(dry weight),which were consistent with the biomass distribution.All results suggested that the final protocol could produce qualified genomic DNA as a template from the BAC filter for downstream molecular biology researches.