Organic gel electrolyte, application, sodium-based double-ion organic solid-state battery and preparation method thereof

Abstract

The invention discloses organic gel electrolyte, application, a sodium-based double-ion organic solid-state battery and a preparation method thereof and relates to the field of electrochemical energystorage devices. The organic gel electrolyte is prepared from electrolyte sodium salt, a non-aqueous solvent and an organic polymer. The sodium-based double-ion organic solid-state battery comprises anegative electrode, a positive electrode, a diaphragm and the organic gel electrolyte; the negative electrode can be sodium ion alloyed metal, a metal alloy or a metal compound; the positive electrode comprises a positive electrode current collector and a positive electrode material; an active substance of the positive electrode material is a laminar material which can be used for reversibly embedding and disembedding sodium salt anions. According to the organic gel electrolyte disclosed by the invention, the problems that organic electrolyte is easy to volatilize, combust and explode, a sodium ion solid-state battery cannot consider ion conducting performance and electrical conductivity at the same time, and the safety performance is not good at high temperature are alleviated. The organic gel electrolyte disclosed by the invention has very good ion conducting performance and electrical conductivity and an electrode piece powdering problem caused by the fact that volume expansion iscaused by alloying can be alleviated; the battery has good circulating stability and safety performance.

Description

technical field [0001] The invention relates to the technical field of electrochemical energy storage devices, in particular to an organic gel electrolyte, its application, a sodium-based double-ion organic solid-state battery and a preparation method thereof. Background technique [0002] Lithium-ion batteries have the advantages of high energy density, high energy efficiency, long cycle life, no memory effect, fast discharge, etc., so they have huge markets in consumer electronics and electric vehicles, power grid peak regulation, energy storage power supplies, aerospace and other fields need. Although the organic electrolyte used in traditional lithium-ion batteries has the advantages of high ionic conductivity, easy control of the electrode / electrolyte interface, and convenient processing, etc., the organic electrolyte is volatile, flammable, and explosive, making batteries especially There are great safety hazards when the capacity is large, and the limited electrochem...

AI Technical Summary

Problems solved by technology

However, ceramic electrolytes still face safety issues caused by high operating temperatures.

The disadvantages of existing all-solid-state sodium-ion batteries are: (1) materials are mostly synthesized by traditional sol-gel method, melting method, mortar sintering and other methods, and the obtained samples are impure and the components are not easy to control; (2) It is difficult to find matching electrodes for the synthesized fast ion conductors, and they generally belong to pure crystals with unstable structures and unstable chemical properties in air, making it difficult to achieve large-scale applications; (3) at room temperature, The conductivity of the all-solid electrolyte is small, and it has good conductivity at high temperature. However, there are safety problems at high temperature.

[0004] CN106532114A proposed a sodium ion solid electrolyte composite material based on NASICON structure and its preparation method and application. In this invention patent, a kind of solid electrolyte composite material based on NASICON structure was synthesized by traditional sol-gel method, and obtained Composite solid electrolyte has an ionic conductivity of 3.4×10 at room temperature -3 S / cm, the starting point of the patent is the preparation of fast ion conductors, more consideration is the ion-conducting performance of solid electrolytes, but the disadvantage is that the conductivity is poor

However, when tin foil is used as the negative electrode, there are also some problems: (1) sodium ion and tin metal undergo a huge volume expansion during the alloying process, resulting in electrode pulverization and battery capacity attenuation; (2) metal tin reacts with the electrolyte at the interface The formed solid electrolyte layer (SEI film) thickens with time, the interface impedance continues to increase, the Coulombic efficiency decreases, and the battery capacity decays; (3) due to the continuous change in the volume of the tin metal negative electrode during charge and discharge, the SEI film is unstable, and in During the process of deintercalating sodium, the continuous formation-cracking-regeneration consumes metal sodium and electrolyte; (4) Traditional secondary batteries mostly use liquid organic electrolytes, which are prone to problems such as liquid leakage and electrode corrosion. explosion occurs

Although these methods have improved the electrochemical performance of sodium-ion batteries to a certain extent, they have brought new problems at the same time: for example, the surface modification is all at the level of inorganic compounds, or the formation of the SEI film will still occur during cycling. There is a case of cracking, or adding an initiator or a cross-linking agent to cause a polymerization reaction may cause thermal expansion and thermal drumming, which will affect the performance of the battery

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