CN102530907A - Method for preparing lithium ion battery anode material manganese lithium phosphate by using sol-gel method - Google Patents

Abstract

The invention discloses a method for preparing a lithium ion battery anode material manganese lithium phosphate by using a sol-gel method. The method comprises the following steps of: dissolving a manganese salt, a lithium salt, a chelating agent and a phosphate into water in a molar ratio of (1.9-2.1): (1.9-2.1): (0.95-1.1): (1.9-2.1), mixing uniformly, adding polyethylene glycol (PEG), regulating the pH to be 9-11 by using 15 mass percent aqueous ammonia, stirring till the solution is viscous, drying, then sintering for 5 to 15 hours in a non-oxidative atmosphere at the temperature of between 400 and 600 DEG C, cooling, and thus obtaining the manganese lithium phosphate. By the method, the raw materials can be mixed to a molecule level in the sol step, so that the calcining temperature is reduced, the manganese lithium phosphate is uniform in particle diameter distribution and fine, the electric conductivity of the manganese lithium phosphate is improved, the cost is reduced, and the electrochemical performance of the manganese lithium phosphate is improved.

Description

Sol-gel method prepares lithium ion battery anode material manganese lithium phosphate

Technical field

The present invention relates to the method that a kind of sol-gel method prepares lithium ion battery anode material manganese lithium phosphate.

Background technology

Lithium ion battery is considered to best at present environmental protection ideal source, receives science and technology and industry member and pays much attention to, and be used widely.LiMnPO ₄Anode material for lithium-ion batteries as having potentiality has high potential, and it is with respect to Li ⁺The electrode potential of/Li is 4.1V, just in time not with the stable electrochemical window of existing electrolyte system.This material has the potential high-energy-density, and abundant raw material, cost are low, environmentally friendly.

LiMnPO ₄Main preparation methods has solid phase method, carbothermic method, hydrothermal method and sol-gel method etc., is difficult to the synthetic chemically active LiMnPO that has through traditional preparation method ₄How control size is big or small, improves specific conductivity and ion diffusion speed and becomes LiMnPO ₄The main direction of research.

Summary of the invention

The object of the present invention is to provide a kind of sol-gel method to prepare anode material for lithium-ion batteries LiMnPO ₄Method.Sol-gel method can arrive molecular level with raw materials mix in the colloidal sol step; Reduce calcining temperature; Organism decomposes generation carbon and is scattered in the presoma equably at pretreatment stage; Effectively suppress too growing up of sample crystal grain, make that the size distribution of sample is even, tiny, specific conductivity improves, cost reduces, thereby improved the chemical property of sample.

Concrete steps of the present invention are:

Mol ratio is respectively 1.9-2.1: 1.9-2.1: 0.95-1.1: mix after 1.9-2.1 manganese salt, lithium salts, sequestrant and phosphoric acid salt are water-soluble; Add polyoxyethylene glycol (PEG); Using mass percent concentration is that 15% ammoniacal liquor is regulated pH at 9-11; Be stirred to thickness, after the drying with its under non-oxidizing atmosphere in 400 ℃-600 ℃ sintering 5-15 hour, cooling obtains lithium manganese phosphate;

Said manganese salt is a kind of in manganous sulfate, manganous nitrate and the manganese acetate;

Said lithium salts is a kind of in Lithium Hydroxide MonoHydrate, lithium nitrate and the Lithium Acetate;

Said sequestrant is a kind of in oxalic acid, Whitfield's ointment and the Hydrocerol A;

Said phosphoric acid salt is primary ammonium phosphate, a kind of in Secondary ammonium phosphate and the ammonium phosphate;

Said polyoxyethylene glycol (PEG) is a kind of among PEG-400, PEG-1000, PEG-2000 and the PEG-10000;

Said non-oxidizing atmosphere is an argon gas, a kind of in nitrogen and the hydrogen;

The present invention has simplified synthesis technique, can suppress too growing up of lithium manganese phosphate crystal grain effectively, makes that institute's synthetic materials size distribution is even, tiny, specific conductivity improves; Adjustable between 400 ℃-600 ℃ of the synthesis temperatures, can obtain varigrained material; Calcination time 5-15 hour, can obtain varigrained material; Method is simple and convenient, be easy to control; The charge-discharge performance of lithium manganese phosphate and cycle performance improve, and have reduced cost.

Description of drawings

Fig. 1 is No. 2 sample LiMnPO of the embodiment of the invention 1 ₄XRD figure.

Fig. 2 is No. 2 sample LiMnPO of the embodiment of the invention 1 ₄SEM figure.

Fig. 3 is No. 2 sample LiMnPO of the embodiment of the invention 1 ₄The first charge-discharge curve.

Embodiment

Embodiment 1:

0.19mol manganese acetate and 0.21mol Lithium Acetate, 0.105mol Hydrocerol A and 0.21mol ammonium di-hydrogen phosphate are mixed after water-soluble; Add PEG-400; Ammoniacal liquor with 15% is regulated pH to 10; Be stirred to thickness, dry back respectively at 400 ℃, 500 ℃, 600 ℃ calcinings 10 hours, is LiMnPO after the cooling under argon gas atmosphere ₄Resulting product shows to be LiMnPO through X-ray diffraction analysis ₄, not having any dephasign, the particle diameter that can obtain product through SEM is about 0.1 μ m.Resulting product is assembled into the experiment button cell surveys its charging and discharging capacity and cycle performance, under the multiplying power of 0.05C, discharge and recharge, loading capacity is seen table 1 after its loading capacity and circulation first 30 times.

The experiment condition of table 1 embodiment 1 and result

Embodiment 2:

0.20mol manganous sulfate and 0.20mol Lithium Hydroxide MonoHydrate, 0.10mol oxalic acid and 0.20mol DAP are mixed after water-soluble; Add PEG-10000; Ammoniacal liquor with 15% is regulated pH to 9; Be stirred to thickness, dry back in 500 ℃ of sintering 5,10 and 15h, is LiMnPO after the cooling under nitrogen atmosphere ₄Resulting product shows to be LiMnPO through X-ray diffraction analysis ₄, not having any dephasign, the particle diameter that can obtain product through SEM is about 0.1 μ m.Resulting product is assembled into the experiment button cell surveys its charging and discharging capacity and cycle performance, under the multiplying power of 0.05C, discharge and recharge, loading capacity is seen table 2 after its loading capacity and circulation first 30 times.

The experiment condition of table 2 embodiment 2 and result

Claims (1)

1. method for preparing lithium ion battery anode material manganese lithium phosphate is characterized in that concrete steps are:

Mol ratio is respectively 1.9-2.1: 1.9-2.1: 0.95-1.1: mix after 1.9-2.1 manganese salt, lithium salts, sequestrant and phosphoric acid salt are water-soluble; Add polyoxyethylene glycol; Using mass percent concentration is that 15% ammoniacal liquor is regulated pH at 9-11; Be stirred to thickness, after the drying with its under non-oxidizing atmosphere in 400 ℃-600 ℃ sintering 5-15 hour, cooling obtains lithium manganese phosphate;

Said manganese salt is a kind of in manganous sulfate, manganous nitrate and the manganese acetate;

Said lithium salts is a kind of in Lithium Hydroxide MonoHydrate, lithium nitrate and the Lithium Acetate;

Said sequestrant is a kind of in oxalic acid, Whitfield's ointment and the Hydrocerol A;

Said phosphoric acid salt is primary ammonium phosphate, a kind of in Secondary ammonium phosphate and the ammonium phosphate;

Said polyoxyethylene glycol is a kind of in polyoxyethylene glycol-400, polyoxyethylene glycol-1000, polyoxyethylene glycol-2000 and the polyoxyethylene glycol-10000;

Said non-oxidizing atmosphere is an argon gas, a kind of in nitrogen and the hydrogen.

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