3D porous current collector and preparation method and application thereof

Abstract

The invention relates to a 3D porous current collector and a preparation method and application thereof. The preparation method herein includes: punching a copper foil to obtain a disc, washing the disc sequentially with acetone, ethanol, hydrochloric acid and deionized water, soaking the washed disc in a mixed solution of ammonium persulfate and sodium hydroxide for 15 min, taking out, washing sequentially with deionized water and ethanol, drying in air for 12 hours, heating from room temperature to 180 DEG C, holding the temperature for 4 hours, cooling with a gas to room temperature to obtain the 3D porous current collector. A layer of copper oxide nanowire array is grown on a copper foil by an in-situ process herein; the presence of the copper oxide nanowire array helps increase the specific surface area of the current collector, and reduce local current density of electrode surface; a battery with the current collector provided herein has coulombic efficiency kept to 90% and aboveafter 100 cycles under normal temperature and the current density of 0.5 to 1 mA / cm<2>.

Description

technical field [0001] The invention relates to the technical field of energy storage, in particular to a 3D porous collector and its preparation method and application. Background technique [0002] With the successful commercial application of graphite anodes, lithium-ion batteries have been widely used in portable electronic devices such as smartphones and laptops. [0003] Lithium metal batteries with metallic lithium as the negative electrode, including lithium-sulfur batteries, lithium-oxygen batteries, and lithium-oxide batteries, exhibit extremely high theoretical energy densities (lithium-oxygen batteries: 3500Wh kg -1 , lithium-sulfur battery: 2600Wh kg -1 , lithium oxide battery: 1000-1500Wh kg -1 , the current lithium-ion battery: 500-1000Wh·kg -1 ). Among them, lithium metal has the lowest density in nature (0.53g / cm 3 ), the metal element with the lowest standard potential (-3.04V vs. SHE), the lowest electrochemical equivalent (0.26g / Ah), and the highest ...

AI Technical Summary

Problems solved by technology

While lithium metal anode has excellent theoretical performance, it also has serious practical bottlenecks. Its advantages and problems include: (1) lithium metal has high reactivity and extremely low electrode potential. It brings extremely high theoretical energy density, but its high activity brings serious side reactions between metal lithium and electrolyte, which makes the active material be irreversibly consumed, resulting in low utilization efficiency of metal lithium anode

(2) Lithium metal is a conversion-type negative electrode with conductivity, which itself is an electron channel. In theory, the charging and discharging process can be completed without an external skeleton, but the actual lithium metal negative electrode has dendrite growth and volume expansion effects. Seriously affect the battery utilization rate and service life during its actual operation, which limits the practical application of metal lithium anodes

The above-mentioned problems are either directly caused by dendrite growth or further exacerbated by dendrite growth.

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