Study On The Controllable Fabrication And Properties Of Aspergillus Niger Derived Anode Material For Energy Storage Battery

With the increasing of energy consumption demands,lithium/sodium/potassium ion batteries have been widely studied.As an important component of lithium/sodium/potassium ion batteries,anode materials have attracted intensive attention of researchers.Transition metal sulfide?MS_x,M=Ni Co Mn Mo,etc.?has become a competitive anode materials of lithium/sodium/potassium ion battery due to its excellent reversibility and high theoretical capacity.Unfortunately,the volume change in the process of charging and discharging leads to the poor cycling stability and multiplier performance of MS_x,which seriously hinders its development and practical application.As a promising modification material,carbon material can not only improve the conductivity of the material but also inhibit the volume variation of transition metal sulfide,as well as promote the migration of electrons,thus further improve the performance and stability of the battery.However,finding an environmentally friendly,low cost,large-scale and universally applicable carbon material remains a challenge.To solve these problems,a one-dimensional layered carbon fiber and transition metal sulfide nanocrystals/carbon fiber composites are constructed by a general metal-aspergillus niger bioleaching strategy.1.We develop a general metal-aspergillus niger bioleaching approach for preparing novel fungus–inspired electrode materials that may deliver high properties lithium–ion/sodium–ion batteries with one–dimension architectures.The fungus function as natural templated to provide a large of nitrogen/carbon source,which are functionalized with metal sulfides nanoparticles,yielding various metal sulfides nanoparticles/nitrogen–doped carbonaceous fibers(MS/NCF(MS=ZnS,Co₉S₈,FeS,Cu_1.81S))with high conductivity.In addition,the as–obtained MS/NCF own uniform fibers architecture and abundant porous structure,which can also enhance the storage ability for LIBs and SIBs.2.A controlled bioleaching strategy to embed Ni₃S₂ nanocrystals into 1D hollow carbonaceous fibers derived from renewable biomass was designed with enough inner voids as well as abundant natural pyridinic and pyrrolic nitrogen.The adsorption capacity and gradient of Ni²⁺can be achieved by tuning the ratio of water and ethanol followed by a morphology change from solid to hollow structure through a simple pyrolysis process.The hollow fiber-based electrode can prevent the large volume expansion,improve the electronic conductivity and enhance the diffusion rate of Li⁺/Na⁺ion.As a result,the synthesized Ni₃S₂/hollow carbonaceous fiber electrodes deliver excellent reversible capacity and outstanding cycle stability,i.e.,673.4 mAh g^-1 at 0.1 A g^-1 after 100 cycles for lithium-ion batteries?LIBs?,378.4 mAh g^-1 at 1 A g^-1 after 100 cycles for sodium-ion batteries?SIBs?,in electrochemical half-cells.More importantly,a superior electrochemical performance is obtained in a full-cell when choosing Na₃V₂?PO₄?₃ as cathode(i.e.,218.9 mAh g^-1 after 100 cycles at 0.5 A g^-1).3.We develop an N/S co-doped layered carbonaceous fiber.Aspergillus Niger was used to adsorb Sn⁴⁺and S^2-ions to form two-dimensional SnS₂ nanosheet and induce the formation of carbon nanosheet,at the same time,Sn catalyzes the surrounding carbon to form graphite structure.After acid treatment,the N/S dual-doped carbonaceous fibers with expanded layer spacing were obtained.The as-prepared NSHCF-600 exhibits a high reversible capacity of 345.4 mA h g^-1 at 0.1 A g^-1 after 100 cycles.The excellent potassium storage performance can be ascribed to the N/S dual-doping,which enlarges interlayer spacing?0.404 nm?and introduces adequate defects.The larger interlayer spacing and higher pyridinic N active sites can promote K ions diffusion and storage.In addation,the ex situ transmission electron microscopy reveals the high reversibility of potassiation/depotassiation process and structural stability.In this thesis,we prepared carbon through biological template,and derived transition metal sulfide nanocrystals/carbonnaceous fibers by special adsorption between Aspergillus niger and metal ions.Eventually,we found excellent Li⁺/Na⁺/K⁺storage capacity by designing their morphology.It provides a renewable and ecology design for lithium/sodium/potassium ion batteries researches with anode materials.