Preparation method, product and application of a positive electrode pre-lithiation material

A positive electrode and lithiation agent technology, which is applied in the field of preparation of positive electrode pre-lithiation materials, can solve the problems of low specific capacity, decomposition and gas production, etc., and achieve the effects of improved stability, high safety, and good chemical stability

Active Publication Date: 2021-10-08
HUAZHONG UNIV OF SCI & TECH +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the specific capacity of these materials is relatively low
Another type of lithium salt such as Li 2 C 4 o 4 , LiC 2 o 2 , Li 2 C 3 o 5 and Li 2 C 4 o 6 Although the specific capacity is high, it will decompose and produce gas during the first charging process

Method used

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  • Preparation method, product and application of a positive electrode pre-lithiation material
  • Preparation method, product and application of a positive electrode pre-lithiation material
  • Preparation method, product and application of a positive electrode pre-lithiation material

Examples

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preparation example Construction

[0031] Preparation method of pre-lithiation agent pole piece

[0032] Me / LiF / Li 2 Mix O and conductive agent (Super~P) evenly, then add polyvinylidene fluoride (PVDF) binder, add a certain amount of N-methylpyrrolidone (NMP), grind evenly, and apply the above mixed slurry on the current collector (such as an aluminum foil current collector), bake at 60° C. and an inert atmosphere for 4 hours, for example, to obtain the required pre-lithiated electrode sheet. Wherein, the formula of the pole piece is (mass ratio) may be pre-lithiation agent: Super~P:PVDF=7:2:1.

[0033] Positive electrode sheet preparation

[0034] Mix the positive electrode active material, pre-lithiation agent and conductive agent (Super~P) evenly, then add polyvinylidene fluoride (PVDF) binder, drop a certain amount of N-methylpyrrolidone (NMP), grind evenly, The above-mentioned mixed slurry is evenly coated on the aluminum foil current collector, and baked at 80° C. under vacuum conditions for 4 hours, f...

Embodiment 1

[0041] Weigh 0.3g FeF 3 After the hydrate was ground in a mortar, it was transferred to a hydrothermal kettle with a capacity of 100mL, and then 75mL of n-propanol was added, sealed and placed in an oven at 200°C for 24h. After the reaction, it was taken out, washed with ethanol, centrifuged three times, and dried in an oven at 60° C. to obtain FeOF solid powder. Then, 0.15 g of FeOF and 0.048 g of metal lithium were weighed in an Ar atmosphere glove box, placed on a heating platform, and molten metal lithium and FeOF were mechanically mixed and reacted at 300° C. After reacting for 1 hour, lower the temperature, and collect black Fe / LiF / Li with a carbon-containing coating layer and a particle size of 2 μm to 20 μm. 2 O powder, Fe, Li 2 The molar ratio of O and LiF satisfies 1:x:y, and 2x+y≤3. Take 7mg of Fe / Li 2 The O / LiF additive was mixed with 2 mg conductive agent (Super~P) and 20 mg PVDF (5wt% PVDF / NMP solution), homogenized, coated, dried in vacuum at 60 ° C, punched...

Embodiment 2

[0044] Weigh 0.3g CoF 3 After the hydrate was ground in a mortar, it was transferred to a hydrothermal kettle with a capacity of 100mL, and then 75mL of n-propanol was added, sealed and placed in an oven at 200°C for 24h. After the reaction, it was taken out, washed with ethanol, centrifuged three times, and then dried in an oven at 60°C to obtain CoOF solid powder. Then, 0.15 g of CoOF and 0.048 g of metal lithium were weighed in an Ar atmosphere glove box, placed on a heating platform, and molten metal lithium and CoOF were mechanically mixed and reacted at 300 ° C. After reacting for 1 hour, lower the temperature, and collect the obtained black Co / LiF / Li 2 O powder, Co, Li 2 The molar ratio of O and LiF satisfies 1:x:y, and 2x+y≤3. Take 7mg of Co / Li 2 The O / LiF additive was mixed with 2 mg conductive agent (Super~P) and 20 mg PVDF (5wt% PVDF / NMP solution), homogenized, coated, dried in vacuum at 60 ° C, punched into pole pieces with a diameter of 10 mm, and Metal lithi...

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Abstract

The invention belongs to the field of lithium ion batteries, and discloses a preparation method, product and application of a positive electrode pre-lithiation material. On a heating platform, heat and mix MeOF and molten metal lithium under a protective gas atmosphere to fully react. After cooling down, you can get MeOF, LiF and Li 2 Me / LiF / Li composed of O 2 O prelithiation agent. In the present invention, by improving the overall process flow of the preparation method, the composition and proportioning ratio of the reaction raw materials, etc., correspondingly, it is possible to obtain 2 Me / LiF / Li composed of O 2 O pre-lithiation agent can solve the problem of loss of lithium ions in the first charge and discharge process of lithium-ion batteries, which leads to the reduction of reversible charge-discharge capacity. The positive electrode pre-lithiation additive is added to the positive electrode to increase the capacity and energy density of lithium-ion batteries.

Description

technical field [0001] The invention belongs to the field of lithium-ion battery energy storage devices, and more specifically relates to a preparation method, product and application of a positive electrode pre-lithiated material. Background technique [0002] The first charge of a lithium-ion battery will form a solid electrolyte interface (SEI) on the surface of the negative electrode. The formation of SEI consumes part of the active lithium ions provided by the positive electrode, resulting in a decrease in the reversible capacity of the battery. At the same time, as the charge-discharge cycle proceeds, side reactions on the electrode surface increase (coulombic efficiency <100%), and active lithium decreases, resulting in poor cycle performance. Especially for the key anode material of high energy density lithium-ion battery——alloy anode material (such as silicon carbon, silicon oxygen and tin, etc.), the coulombic efficiency of material itself is lower than traditio...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H01M4/62H01M10/0525
CPCH01M4/62H01M4/624H01M4/625H01M4/628H01M10/0525Y02E60/10
Inventor 孙永明杜俊谋李政杰夏圣安王涛
Owner HUAZHONG UNIV OF SCI & TECH
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