Novel solid-liquid battery with lithium metal negative electrode and high-voltage positive electrode

Abstract

The invention discloses a novel solid-liquid mixed electrolyte battery with a lithium metal negative electrode and a high-voltage positive electrode. The battery comprises a positive electrode and a negative electrode, the negative electrode is made of metal lithium, a solid electrolyte is arranged between the positive electrode and the negative electrode, the space between the solid electrolyte and the positive electrode is filled with an ester electrolyte, and the space between the solid electrolyte and the negative electrode is filled with an ether electrolyte. On one hand, the ether electrolyte is filled between the lithium metal and the solid electrolyte, so that the cycle life of the lithium metal is prolonged; on the other hand, the ester electrolyte is filled between the positive electrode and the solid electrolyte, so that the selection space of the positive electrode is improved, and the energy density of the battery is improved; besides, the electrolyte is filled, so that the usage amount of the solid electrolyte can be reduced, and the interface impedance of the battery is reduced on the basis of ensuring that the safety is improved by utilizing the solid electrolyte; furthermore, the existence of the solid electrolyte can prevent metal ions dissolved out of the electrolyte from migrating to the surface of the metal lithium to influence the performance of the negative electrode.

Description

technical field [0001] The invention relates to the field of lithium batteries, in particular to a novel solid-liquid battery with lithium metal negative and high voltage positive electrodes. Background technique [0002] At present, there are three types of electrolytes, ether electrolytes, ester electrolytes, and solid electrolytes. Among them, the cycle performance of lithium negative electrodes in ether electrolytes is much higher than that of ester electrolytes, and the lithium metal coulombic efficiency of ether electrolytes can be as high as More than 99.9%, which is very beneficial to the cycle life of lithium metal as the negative electrode. In order to obtain high energy density, the positive electrode needs to be charged to 4.2V or even above 5V. However, the voltage resistance of the ether electrolyte is poor, and it is generally only stable at around 4.0V (vsLi+ / Li), and severe decomposition will occur at higher voltages. , causing battery flatulence and affect...

AI Technical Summary

Problems solved by technology

In order to obtain high energy density, the positive electrode needs to be charged to 4.2V or even above 5V. However, the ether electrolyte has poor voltage resistance and is generally only stable at around 4.0V (vsLi+ / Li), and severe decomposition will occur at higher voltages. , leading to battery flatulence, etc., which affect the cycle performance of the full battery

[0003] However, if the ester electrolyte is used, although the withstand voltage is higher, the coulombic efficiency for lithium metal is mostly below 60%, and the cycle life of lithium metal is severely limited.

If all solid electrolytes are used, the high strength of the solid electrolyte can effectively prevent the dendrite short circuit of the lithium metal negative electrode and improve the safety of the battery. However, on the one hand, the high density of the solid electrolyte will reduce the energy density of the battery. The solid-solid interfacial compatibility of the positive electrode is poor, which will increase the complexity of the battery process

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