Multi-acid Base Composite Solid Electrolyte

Lithium ion battery(LIBs)has become the most significant energy storage equipment due to its superior Performances(high energy density,etc.).The anode,cathode and electrolyte are the key technologies to the lithium ion batteries,among them,the electrolyte material affects the safety performance of the battery.Liquid electrolyte is widely used in the traditional lithium ion battery.It is easy to corrosion of electrodes,even causing security problems.Solid-state lithium-ion batteries can effectively inhibit the growth of lithium dendrites and thus achieve higher energy density,which is considered as a potential candidate for the next generation of energy storage and has become a research hotspot in recent years.As an important component of solid-state lithium-ion batteries,solid electrolytes can be used as a substitute for liquid electrolyte because of its wide working temperature range,easy processing,high mechanical strength,good chemical ana electrochemical stability,and wide working voltage window.At present,there are two kinds of solid electrolytes widely used:inorganic and polymer solid electrolytes.However,for inorganic solid electrolytes,there are some problems,such as easy direct reaction with lithium,unstable contact wiui water and carbon dioxide,increasing interracial resistance with the change of electrode volume during the cycle,difficult processing and high cost,which are difficult to meet the practical application requirements.In contrast,solid-state Polymer electrolytes have good processing flexibility,can effectively overcome the interface resistance and inhibit the growth of lithium dendrites.These advantages make solid-state polymer electrolytes have broad application prospects.Nowadays,solid-state polymer electrolytes are usually based on PEO or PSS polymer and single lithium ion salts(such as LiTFSI or LiClO4)composite ionic conductive materials,but these materials usually show low ionic conductivity,which is difficult to meet the practical application requirements(10-4 S cm-1).Therefore,the design and construction of new ionic conductive materials to achieve high ionic conductivity is currently a worldwide research hotspot and difficulty.Polyoxometalates are a class of materials with nano-size,adjustable structure,oxygen-rich surface and strong redox properties,which are composed of counteracting cations and heteropoly anions.In view of its abundant counterion cations,it has great potential application prospectsi n ionic conduction,but there is no precedent for the application of polyoxometalates in ionic conduction.In this paper,we take polyoxometalates as the precursor which compounded with metal organic frameworks material and polymer containing sulfonic acid for application in electrochemical energy storage.The specific works are as follows:(1)We present an alternative facile and scalable polyoxovanadate-induced self-assembly method for the fabrication of POVs/PSS one-dimensional hybrid nanowires.the POVs/PSS hybrid nanowires with aligned one-dimensional nanowire morphology present highest Li+,Na+and K+ conductivity(25?,5 3.30 × 10-3,2.00 ×10-3 and 1.23 × 10-3 S cm-1;70 ?,2.00 ×10-1,3.00 × 10-2 and 1.71 × 10-2 S cm-1,respectively)in polymer based electrolytes.Moreover,V15/PSS-Li-1 was successfully used as an electrolyte to assemble solid-state lithium batteries(Li/(V15/PSS-Li-1)/LiFePO4)with excellent electrochemical performance.(2)A series of POVs/polymer one-dimensional hybrid nanowire materials based on different polyoxometalates(K10V34,K7V15 and HK5V10)and different sulfonated polymer monomers(SS,SAS and AMPS)were successfully synthesized by polyoxometalates-indueed self-assembly,which possess outstanding K+ conductivity performance.POVs/PSAS-K hybrid nanowires with aligned one-dimensional nanowire morphology exhibit highest K+ conductivity(25?,4.74 × 10-3 S cm-1;70?,6.52 × 10-2 S cm-1)in polymer based electrolytes.(3)The integrated electrode materials of HP-POMOFs/CC were prepared by in-situ hot pressing method with PMo12,copper(?)acetate monohydrate(Cu(CH3COO)2·H2O),and 1,3,5-benzenetricarboxylate(H3BTC)as precursor,further used as anode material for lithium ion batteries.Three-dimensional flexible CC is used as a current collector improved the electronic conductivity of electrode.POMs are loaded into MOFs to construct POMOFs materials,not only reduce the dissolution of POMs in electrolyte,but also enhance the electrochemical stability.HP-POMOFs/CC acts as integrated electrode,successfully avoiding using polymer binder,reducing the inactive interface.HP-POMOFs/CC display excellent electrochemical performances for lithimn storage at the current density of 200 mA g-1.