CN115650216A - Method for preparing graphene nanosheets by utilizing graphite ball milling of negative electrodes of waste lithium batteries and application of graphene nanosheets - Google Patents
Method for preparing graphene nanosheets by utilizing graphite ball milling of negative electrodes of waste lithium batteries and application of graphene nanosheets Download PDFInfo
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Abstract
The invention discloses a method for preparing graphene nanosheets by utilizing graphite ball milling of negative electrodes of waste lithium batteries and application thereof, wherein the method comprises the steps of pretreating, soaking negative electrode powder of the waste lithium batteries in clear water for a period of time, filtering, collecting filter residues, roasting the filter residues, and collecting residual waste stone and ink powder; ball milling, namely mixing and ball milling the waste graphite powder and the interlaminar stripping agent powder; and (3) cleaning, cleaning and filtering the ball-milled product, and drying the obtained filter residue to obtain the finished graphene nanosheet. The method can recycle the waste graphite of the waste lithium battery, is used for preparing the graphene nanosheet with high added value, and realizes recycling of the waste graphite of the cathode of the waste lithium battery.
Description
Technical Field
The invention belongs to the technical field of lithium battery recovery, and particularly relates to a method for preparing graphene nanosheets by utilizing graphite ball milling of a negative electrode of a waste lithium battery and application of the graphene nanosheets.
Background
China starts to enter a large-scale decommissioning period of power lithium batteries from 2018, the GWH reaches 7.0 in the end of the year, the decommissioning of the power lithium batteries reaches about 25.6GWH in 2020, the decommissioning of the power lithium batteries reaches 174.2GWH (about 200 ten thousand tons) in 2025, and the composite growth rate reaches 58.2%. The retired power lithium battery is composed of precious metals, high-quality graphite, organic electrolyte and other components, and if reasonable recycling cannot be conducted, huge resource waste and serious environmental pollution can be caused.
At present, researches and industries at home and abroad mainly focus on recycling precious metal materials of lithium battery anodes, for example, chinese invention patent "a lithium battery anode material recycling system and a recycling method thereof" (Zhang Shanshan et al, patent No. CN 202010522498.3), a constant-temperature magnetic stirrer is used for heating an extraction solution of the lithium battery anode at an accurate temperature, a charging hopper is used for accurately controlling the charging amount of each auxiliary material, a barrel and a filter screen are used for conveniently filtering and receiving filtrate, and materials such as FePO powder and LiCO in the lithium battery anode are rapidly recycled.
Meanwhile, the value of the graphite of the negative electrode of the waste lithium battery is often neglected. In fact, graphite used for lithium ion battery production is subjected to processes of surface oxidation, lattice expansion and the like after being subjected to links such as acid washing, high temperature and the like in recovery, so that the graphite interlayer spacing is enlarged, stripping is very easy to occur under mechanochemical action, and a graphene product with high added value is generated.
Disclosure of Invention
This section is for the purpose of summarizing some aspects of embodiments of the invention and to briefly introduce some preferred embodiments. In this section as well as in the abstract and title of the application, simplifications or omissions may be made to avoid obscuring the purpose of the section, the abstract and the title, and such simplifications or omissions are not intended to limit the scope of the invention.
The present invention has been made keeping in mind the above and/or other problems occurring in the prior art.
One of the purposes of the invention is to provide a method for preparing graphene nanosheets by ball milling of negative graphite of waste lithium batteries, which can recycle the waste graphite of the waste lithium batteries to prepare the graphene nanosheets with high added values, so that the waste graphite of the negative electrodes of the waste lithium batteries can be recycled.
In order to solve the technical problems, the invention provides the following technical scheme: a method for preparing graphene nanosheets by utilizing graphite ball milling of a negative electrode of a waste lithium battery comprises the following steps,
pretreating, namely soaking the negative electrode powder of the waste lithium battery in clear water for a period of time, filtering, collecting filter residues, roasting the filter residues, and collecting residual waste stone and ink powder;
ball milling, namely mixing and ball milling the waste graphite powder and the interlaminar stripping agent powder;
and (3) cleaning, cleaning and filtering the ball-milled product, and drying the obtained filter residue to obtain the finished graphene nanosheet.
As an optimal scheme of the method for preparing the graphene nanosheets by utilizing graphite ball milling of the negative electrode of the waste lithium battery, the method comprises the following steps: in the ball milling, the molar ratio of the waste graphite powder to the interlaminar stripping agent powder is 1: 2-6, wherein the interlaminar stripping agent is solid powder which can generate intercalation with graphite, and comprises one of ammonium chloride, ammonium carbonate, ammonium sulfate and potassium chloride.
As an optimal scheme of the method for preparing the graphene nanosheets by utilizing graphite ball milling of the negative electrode of the waste lithium battery, the method comprises the following steps: in the ball milling, the ball milling time is 0.5 to 3 hours, and the ball milling frequency is 20 to 30Hz.
As an optimal scheme of the method for preparing the graphene nanosheets by utilizing the graphite ball milling of the negative electrode of the waste lithium battery, the method comprises the following steps: in the ball milling, the diameter of a small ball used for ball milling is 2-5 mm, the ball-to-material ratio is 12-18: 1.
as an optimal scheme of the method for preparing the graphene nanosheets by utilizing the graphite ball milling of the negative electrode of the waste lithium battery, the method comprises the following steps: in the pretreatment, the times of soaking and filtering are 3 times, and the soaking time is 3 to 4 hours each time.
The invention utilizes the waste lithium batteryAn optimal scheme of the method for preparing the graphene nanosheets by graphite ball milling with the pool negative electrode is as follows: in the pretreatment, the calcination is carried out in a nitrogen atmosphere with a nitrogen flow of 100m 3 /h。
As an optimal scheme of the method for preparing the graphene nanosheets by utilizing graphite ball milling of the negative electrode of the waste lithium battery, the method comprises the following steps: in the pretreatment, the roasting temperature is 500 ℃ and the roasting time is 2 hours.
As an optimal scheme of the method for preparing the graphene nanosheets by utilizing graphite ball milling of the negative electrode of the waste lithium battery, the method comprises the following steps: in the cleaning, the filtrate obtained by filtering is dried, and the product obtained by the treatment is ammonium chloride and is used for ball-milling and mixing with waste stone powdered ink again.
It is another object of the present invention to provide graphene nanoplatelets prepared by the method as described in any one of the above.
Another object of the present invention is to provide the use of graphene nanoplatelets as described above in the modification of silicone rubber.
Compared with the prior art, the invention has the following beneficial effects:
the method can recycle the waste graphite of the waste lithium battery, is used for preparing the graphene nanosheet with high added value, and realizes recycling of the waste graphite of the cathode of the waste lithium battery.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive exercise. Wherein:
fig. 1 is an XRD pattern of different graphene nanoplatelets obtained in example 1 of the present invention;
fig. 2 is a raman diagram of different graphene nanoplatelets obtained in example 1 according to the present invention;
fig. 3 is an XRD pattern of different graphene nanoplates obtained in example 2 of the present invention;
fig. 4 is a raman diagram of different graphene nanoplatelets obtained in example 2 of the present invention;
fig. 5 is an XRD pattern of different graphene nanoplatelets obtained in example 3 of the present invention;
fig. 6 is a raman chart of different graphene nanoplates obtained in example 3 of the present invention;
fig. 7 is a schematic diagram of a mobile phone shell prepared from the graphene-modified silica gel obtained in example 5 according to the present invention, the mobile phone shell being naturally cooled from 60 ℃ to 20 ℃ at a room temperature of 15 ℃.
Detailed Description
In order to make the aforementioned objects, features and advantages of the present invention more comprehensible, specific embodiments thereof are described in detail below with reference to examples of the specification.
In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, but the present invention may be practiced in other ways than those specifically described and will be readily apparent to those of ordinary skill in the art without departing from the spirit of the present invention, and therefore the present invention is not limited to the specific embodiments disclosed below.
Furthermore, the references herein to "one embodiment" or "an embodiment" refer to a particular feature, structure, or characteristic that may be included in at least one implementation of the present invention. The appearances of the phrase "in one embodiment" in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments.
Example 1
(1) Soaking the waste lithium battery cathode powder in clean water, filtering, and repeatedly treating for 3 times, wherein the soaking time is 3h each time. The obtained filtrate contains a small amount of electrolyte, a binder and lithium ions between graphite intercalation layers, and the filter residue is crude waste graphite powder.
(2) Placing the crude waste graphite powder prepared in the step (1) into a roasting furnace, introducing nitrogen gas into the furnace, and setting the atmosphere flow to be 100m 3 H, preserving the heat of the system at 500 ℃ for 2 hours, and obtaining finished waste graphite after roastingAnd (3) powder. In the roasting process, residual organic electrolyte and the binder are volatilized from the surface of the waste graphite, and the volatilized gas is absorbed by a tail gas absorption device.
(3) Placing the finished waste rock ink powder prepared in the step (2) into a ball mill, adding ammonium chloride powder into the ball mill, controlling the molar ratio of waste graphite to ammonium chloride to be 1: 1, ball-milling to obtain a product of graphene nanosheets and excessive ammonium chloride powder.
(4) Dissolving the product obtained in the step (3) with clear water, filtering, repeatedly treating for 2 times, wherein the filtrate is an ammonium chloride solution, and drying filter residues to obtain a finished graphene nanosheet;
(5) And (4) drying the filtrate in the step (4) in a dryer to obtain ammonium chloride powder, and performing ball milling in the step (3).
The molar ratio of waste graphite to ammonium chloride is calculated as 1. It was found that when the amount of ammonium chloride added was too large, the yield decreased significantly, indicating that the presence of ammonium chloride had greatly affected the exfoliation of the graphite.
As shown in fig. 1, as the molar ratio of graphite to ammonium chloride is changed from 1 to 1, the strength of the (002) crystal face tends to increase, which means that when the addition amount of NH4Cl is large, the influence of the ball milling process on the graphite structure is reduced.
Fig. 2 shows raman spectra of the waste graphite and graphene nanoplatelets obtained at different molar ratios of the waste graphite to ammonium chloride, fig. 2a is a raman spectrum of the graphene nanoplatelets obtained at different molar ratios of the waste graphite to ammonium chloride, and fig. 2b is a ratio (ID/IG) of a D peak intensity and a G peak intensity in fig. 2 a.
From fig. 2, it can be seen that when the molar ratio of the waste graphite to the ammonium chloride is adjusted during the ball milling process, the raman peak intensity of the obtained graphene product changes, and as the ratio of the ammonium chloride increases, the ID/IG value for representing the defect degree of the sample tends to decrease first and then increase. When the molar ratio is 1: when 3, the defect value of the prepared graphene product is the lowest, and when ID/IG =0.37, the molar ratio of the waste graphite to the ammonium chloride is 1: the preferable embodiment is 3.
Example 2
(1) Soaking the waste lithium battery cathode powder in clean water, filtering, and repeatedly treating for 3 times, wherein the soaking time is 3h each time. The obtained filtrate contains a small amount of electrolyte, a binder and lithium ions between graphite intercalation layers, and the filter residue is crude waste graphite powder.
(2) Placing the crude waste graphite powder prepared in the step (1) in a roasting furnace, introducing nitrogen atmosphere into the furnace, and setting the atmosphere flow to be 100m 3 And h, preserving the temperature of the system at 500 ℃ for 2 hours, and obtaining the finished product waste graphite powder after roasting. In the roasting process, residual organic electrolyte and the binder are volatilized from the surface of the waste graphite, and the volatilized gas is absorbed by a tail gas absorption device.
(3) Putting the waste graphite powder finished product prepared in the step (2) into a ball mill, adding ammonium chloride powder into the ball mill, controlling the molar ratio of waste graphite to ammonium chloride to be 1: 1, ball-milling to obtain a product of graphene nanosheet and excessive ammonium chloride powder.
(4) Dissolving the product obtained in the step (3) with clear water, filtering, repeatedly treating for 2 times, wherein the filtrate is an ammonium chloride solution, and drying filter residues to obtain a finished graphene nanosheet;
(5) And (4) drying the filtrate in the step (4) in a dryer to obtain ammonium chloride powder, and performing ball milling in the step (3).
According to calculation, under the conditions that the ball milling frequencies are respectively 15Hz, 20Hz, 25Hz and 30Hz, the yields of the obtained graphene nanosheets are respectively 0.82%, 0.08%, 3.12% and 5.51%. When the ball milling frequency is 15Hz and 20Hz, the yield of the graphene nano sheets is less than 1%, which shows that the graphite stripping is very insufficient, and when the ball milling frequency is increased to 25Hz and 30Hz, the yield of the graphene nano sheets is obviously increased, namely 25Hz can be a boundary point, and a large amount of graphite is stripped after 25 Hz.
The XDR patterns of the waste graphite and the graphene nanoplatelets obtained at different frequencies are shown in FIG. 3, and after ball milling, although the frequency is abnormally increased at 15Hz, the strength corresponding to (002) crystal faces tends to be reduced as a whole. When the ball milling frequency, i.e., the force, is small, the effect of the ball milling is insignificant, whereas when the force is too large, the size of the graphene nanosheet layer may decrease.
Fig. 4 shows raman spectra of the waste graphite and the graphene nanoplatelets obtained at different frequencies, fig. 4a is a raman spectrum of the graphene nanoplatelets obtained at different molar ratios of the waste graphite to ammonium chloride, and fig. 4b is a ratio (ID/IG) of the D peak intensity and the G peak intensity in fig. 4 a.
From fig. 4, it can be found that the value of id/IG gradually increases from 20Hz to 30hz, which indicates that in a certain range, the increase of the ball milling frequency can increase the defect degree of the graphene nanoplatelets.
Example 3
(1) Soaking the waste lithium battery cathode powder in clean water, filtering, and repeatedly treating for 3 times, wherein the soaking time is 3h each time. The obtained filtrate contains a small amount of electrolyte, a binder and lithium ions between graphite intercalation layers, and the filter residue is crude waste graphite powder.
(2) Placing the crude waste graphite powder prepared in the step (1) into a roasting furnace, introducing nitrogen gas into the furnace, and setting the atmosphere flow to be 100m 3 And h, preserving the heat of the system at 500 ℃ for 2 hours, and obtaining the finished product waste graphite powder after roasting. In the roasting process, residual organic electrolyte and the binder are volatilized from the surface of the waste graphite, and the volatilized gas is absorbed by a tail gas absorption device.
(3) Placing the waste stone powdered ink prepared in the step (2) into a ball mill, adding ammonium sulfate powder into the ball mill, controlling the molar ratio of waste graphite to ammonium sulfate to be 1: 1, ball-milling to obtain a product of graphene nanosheets and excessive ammonium sulfate powder.
(4) Dissolving the product obtained in the step (3) by using clear water, filtering, repeatedly treating for 2 times, wherein the filtrate is an ammonium sulfate solution, and drying the filter residue to obtain a finished graphene nanosheet;
(5) And (4) drying the filtrate in the step (4) in a dryer to obtain ammonium sulfate powder, and performing ball milling in the step (3).
By calculation, the yields of the obtained graphene nanosheets are 0.97%, 1.77%, 3.12% and 9.29% respectively under the condition that the ball milling time is 0.5h, 1h, 2h and 3h. The ball milling time is increased from 0.5h to 3h, and the yield of the graphene nano-sheets is increased along with the increase of the ball milling time.
XDR graphs of the waste graphite and the graphene nanosheets obtained under different ball milling times are shown in figure 5, and XRD graphs of graphite samples under different ball milling times show stronger regularity, so that after ball milling, the intensity of a diffraction peak corresponding to a (002) crystal face is obviously reduced, and is reduced along with the increase of the ball milling time. In addition, the half-width of the diffraction peak showed a tendency to increase as a whole with the ball milling time, except for an abnormal decrease at 2 h. This indicates that the effect of the ball milling time on the graphite material is mainly reflected in both lamella thinning and grain reduction.
Fig. 6 shows raman spectra of graphene nanoplatelets obtained by waste graphite at different ball milling times, fig. 6a is a raman spectrum of graphene nanoplatelets obtained at different ball milling times, and fig. 6b is a ratio (ID/IG) of D peak intensity and G peak intensity in fig. 6 a.
It can be seen from fig. 6 that the raman peak intensity of the obtained product also changes with a certain change when the ball milling time is adjusted. When the ball milling time is 2 hours, the ID/IG defect value of the prepared graphene product is the lowest, and the ID/IG =0.44 at the time, so that the ball milling time is 2 hours, which is a preferable technical scheme.
Example 4
The process is optimized according to industrial standards, the whole process is enlarged, and the economic evaluation is carried out on the flow of the waste graphite recovery treatment so as to research the practicability of the process in the actual production process.
Assuming that 1 ton of waste graphite is processed per day, the economic profit (R) of the entire process can be calculated by equation (1), where cost is represented by C and income is represented by P. Cost C here is mainly calculated from cost C of waste graphite recovery r And cost of process recovery C p (formula (2)), the income P is mainly calculated as the sales income of the product, namely, graphene nanoplatelets.
R＝P-C (1)
C＝C r -C p (2)
In order to realize the industrial feasibility of the process and the convenience of calculation, the method subdivides the whole ammonium chloride auxiliary ball milling technology for recovering the waste graphite into four steps which are respectively (1) a waste graphite purification process; (2) an ammonium chloride-assisted ball milling process; (3) leaching the ball-milled product; and (4) an ammonium chloride recovery process. The raw materials used in the process flow are anode graphite powder treated by the waste lithium ion battery, and may contain a very small amount of copper scraps and electrolyte.
The cost expenditure for each specific recovery process is mainly composed of the following parts, which are calculated as follows:
(a) Depreciation fee of equipment
And (3) calculating the depreciation cost of the equipment, considering the influence of the residual rate of the equipment, wherein C0 is the purchase cost of the equipment, and the effective service life of the equipment in one year is assumed to be 300 days. s is the residual value rate of the equipment, 4% is selected here, r is the interest rate, 10% is selected here, and y is the service life of the equipment.
(b) Equipment maintenance fee
The equipment maintenance fee is calculated by the following formula (4), wherein C0 is the equipment purchase cost, and the equipment maintenance fee is 5% of the equipment purchase cost.
C M ＝C 0 ×5％ (4)
(c) Electric charge
Calculating the electric charge, specifically referring to formula (5), wherein P is the working power of the equipment and is in kW; t is the working time of the equipment every day, and h is taken as a unit; e0 is the unit price of industrial electricity, and the reference peak time price is 0.98/kWh.
C E ＝P×t×E 0 (5)
(d) Water fee
The water charge is calculated by the formula (6), wherein V is the water consumption per day in tons, W0 is the unit price of industrial electricity, the peak price is W0, and the standard price is 4.1/ton.
C W ＝V×W 0 (6)
(e) Cost of auxiliary materials
The calculation of the charge of the auxiliary materials, see formula (7), is carried out by calculating the unit price (p) and the corresponding amount (m) of each auxiliary material.
(f) Worker's wage
The worker wages are calculated according to the formula (8), wherein q is the number of workers, L0 is the daily pay of each worker, the average wage of workers in Shanghai regions is 6400/month, the workers work for 25 days in one month and work for 8 hours each day, and the daily pay of the workers in the factory is 256.
C L ＝L 0 ×m (8)
Based on the above calculation formula, the cost of four process procedures corresponding to the single ton of waste graphite treatment can be obtained, and the equipment parameters, material cost and specific operation process of each subsequent process procedure refer to the equipment and literature records in the current market. Suppose that the process treats 1 ton of waste lithium ion battery negative graphite per day.
Based on the calculation mode, the cost of the whole ammonium chloride auxiliary ball milling technology for recycling the waste graphite treatment process is calculated.
(1) Waste graphite cleaning process
The process is as follows: the method comprises the steps of firstly, carrying out impurity removal and purification on a very small amount of copper scraps and electrolyte possibly existing in the waste graphite, supposing that the amount of the copper scraps existing in 1 ton of graphite is 1 percent, namely 0.01 ton, dissolving the copper scraps by using a mixed solution of hydrogen peroxide and hydrochloric acid, wherein 30 percent of hydrochloric acid is 0.036 ton, the unit price is 500/ton, and 50 percent of hydrogen peroxide is 0.01 ton, and the unit price is 2000/ton. The solid-liquid ratio is set to be 50g/L, the water consumption in the process is about 21 tons, and 2 workers are equipped for operation. 2 bag type filters (purchase cost: 160000/machine, working power: 15kW, equipment service life: 5 years, single maximum working capacity: 1.5 tons/h) are used for filtering the waste graphite, and 2 workers are equipped for working for 8 hours per day. In the process of drying the waste graphite, 1 dryer (purchase cost: 95000/machine, working power: 20kW, equipment durability: 5 years) is required, and about 2 hours is required for drying 250kg of samples, so that the equipment works for 8 hours a day, and 2 workers are equipped to operate and clean the equipment. Removing a small amount of electrolyte in the waste graphite by a roasting mode, and equipping 2 heating furnaces (the purchase cost is 1000000/machine, the working power is 35kW, the equipment service life is 5 years, the maximum working capacity of each heating furnace is 250 kg/h), wherein the operation cycle comprises the processes of heating up, heat preservation and cooling down, the heating up and heat preservation time is about 2 hours, the total time is about 3 hours, the working time of each machine per day is 6 hours, the effective electricity utilization time is 4 hours, and equipping 2 operating and cleaning machines for workers.
TABLE 1 cost calculation for waste ink purification Process
As shown in Table 1, the total cost of the purification process of waste graphite was 6463.7 yuan, and 989kg of pure waste graphite could be obtained through the process, assuming that the loss rate of waste graphite in the process was 1%.
(2) Ammonium chloride assisted ball milling process
The process is as follows: in the process, 1 ton of waste graphite needs to be treated, and about 14 tons of ammonium chloride are needed according to the molar ratio of 1. The whole ball milling process is carried out in an industrial ball mill, the purchase price of equipment is 600000 per machine, the working power is 45kW, the maximum working capacity of a single machine is 5 tons, the single machine needs to work for 6 hours every day according to the ball milling time of 2 hours, the service life of the equipment is 5 years, and 2 workers are equipped to operate the equipment.
TABLE 2 ammonium chloride assisted ball milling Process cost calculation
As shown in Table 2, the total cost of the ammonium chloride-assisted ball milling process was 11182.6 RMB, and about 15 tons of a ball-milled product containing about 14 tons of ammonium chloride was obtained. It should be noted that the subsequent ammonium chloride recovery process requires deduction of the cost corresponding to the amount of recovered ammonium chloride.
(3) Ball milling product leaching process
The process is as follows: and (3) carrying out washing filtration for 2 times and drying treatment for 1 time on the ball-milled product obtained in the fourth process step, wherein 37.2g of ammonium chloride can be dissolved in 100g of water at 20 ℃ according to the solubility of the ammonium chloride, and the water consumption in the process is about 8 tons, and 2 workers are equipped for operation. The method is characterized in that 1 bag type filter is used for filtering the ammonium chloride ball-milled graphite, the equipment purchase cost is 160000/machine, the working power is 15kW, the equipment service life is 5 years, the maximum working capacity of each machine can reach 2 tons/h, each machine works for 4h every day, and 2 workers are equipped. In the process of drying the ammonium chloride ball-milled graphite, 1 drier is required, the equipment purchase cost is 95000 per machine, the working power is 20kW, the service life of the equipment is 5 years, and about 2 hours are required for drying a 250kg sample, so that the work for treating a single ton of waste graphite is required for 8 hours, and 2 workers are required to operate and clean the equipment.
TABLE 3 ball-milling product Leaching Process cost calculation
As shown in Table 3, the total cost of the ammonium chloride assisted ball milling process was 2208.4, and considering that the graphite had a certain loss during the process, the final ammonium chloride ball milled graphite product was about 979kg assuming a loss rate of 1%.
(4) Ammonium chloride recovery process
The process is as follows: and (4) evaporating and crystallizing the leachate obtained in the fifth technical process to recover ammonium chloride. The purchase price of each set of equipment is 100000, the working power of each set of equipment is 15kW, and the filtering efficiency is 1 ton/h, so that about 8 hours is required for 8 tons of leachate, and two workers are equipped for operation.
TABLE 4 ammonium chloride recovery Process cost calculation
As shown in Table 4, the total cost of the ammonium chloride recovery process is 730.6, and the evaporated water vapor can be used continuously after being condensed, so that the actual cost is lower than the calculated value. According to the results of the actual experiments on the ammonium chloride obtained by the final evaporative crystallization, 91.6% of the ammonium chloride can be recovered, which means that the actual consumption of 14 tons of ammonium chloride in a complete process flow is 1.2 tons.
The cost Cp of the whole process for treating single ton of waste graphite is 11985.3/ton by combining the calculation of the four process stages. According to the fact that the recovery price Cr of a single ton of waste graphite on the market is about 2000/ton, the total cost C for treating 1 ton of waste graphite per day is 13985.3. The final obtained graphene nano sheet is 979kg, and the minimum sale price of the graphene nano sheet in the market is 20/kg, so that the input (P) of single ton of waste graphite treatment is 19580/ton. Therefore, the profit of recycling the waste battery cathode graphite to process a single ton of waste graphite in a single day in the whole process is 5594.7/ton.
According to the fact that the purchase capital M of the equipment is 3370000, the operating time of the factory is 300 days each year, then the operating time Y is 603 days, namely about two years, and the profit can cover the cost of purchasing the machine.
Example 5
The graphene nanosheet obtained in the example 1 is applied to modification of a silicone rubber material, the graphene nanosheet and the silicone rubber raw material are uniformly mixed by a twin-roll open mill, the mixing temperature is 40 ℃, the mixing time is 90 minutes, and the mixing amount of the graphene nanosheet is respectively 0.5wt.%, 1.0wt.% and 1.5wt.%, so that the graphene modified silica gel is obtained.
The ordinary silicone rubber and the graphene modified silicone rubber obtained in example 6 were tested for thermal diffusivity and thermal conductivity by a laser flash method using a laser thermal conductivity meter. The test results are shown in table 5.
TABLE 5
As can be seen from the data in table 5, the thermal diffusion coefficient and the thermal conductivity of the silica gel can be significantly increased by modifying the graphene nanosheets, and the thermal diffusion coefficient and the thermal conductivity of the graphene-modified silica gel gradually increase with the increase of the mixing amount of the graphene nanosheets.
The graphene modified silica gel obtained in the embodiment 5 is made into a mobile phone shell by a hot press molding method, and the obtained mobile phone shell is subjected to a cooling test by heating the mobile phone shell to 60 ℃ through a constant temperature heating table under the observation of an infrared imager, then immediately transferring the mobile phone shell into a constant temperature environment, and observing and recording the time for reducing the average temperature of the surface of the mobile phone shell to 20 ℃.
The schematic diagram of the time required for the mobile phone shell prepared from the common silicone rubber and the graphene modified silica gel to naturally cool from 60 ℃ to 20 ℃ at the room temperature of 15 ℃ is shown in fig. 7. As can be seen from fig. 7, the time consumed for cooling can be significantly reduced by modifying the graphene nanosheets, and the time consumed for cooling the mobile phone case is gradually shortened along with the increase of the mixing amount of the graphene nanosheets, which is consistent with the thermal conductivity test result.
By the method, the graphene nanosheets can be successfully synthesized from the waste graphite, so that the waste graphite of the negative electrode of the waste lithium battery can be recycled. On one hand, the low-carbon treatment of the waste lithium battery is realized, and on the other hand, the successfully synthesized graphene nanosheet can be widely used as a high-added-value product for the production of high-end products in multiple fields such as electronics, building materials, biology and the like, and accords with the green low-carbon recovery concept.
It should be noted that the above-mentioned embodiments are only used for illustrating the technical solutions of the present invention and not for limiting, and although the present invention is described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions can be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, which should be covered by the claims of the present invention.
Claims (10)
1. A method for preparing graphene nanosheets by graphite ball milling of negative electrodes of waste lithium batteries is characterized by comprising the following steps: comprises the steps of (a) preparing a mixture of a plurality of raw materials,
pretreating, namely soaking the negative electrode powder of the waste lithium battery in clear water for a period of time, filtering, collecting filter residues, roasting the filter residues, and collecting residual waste stone and ink powder;
ball milling, namely mixing and ball milling the waste graphite powder and the interlaminar stripping agent powder;
and (3) cleaning, cleaning and filtering the ball-milled product, and drying the obtained filter residue to obtain the finished graphene nanosheet.
2. The method for preparing graphene nanoplatelets by using graphite ball milling of the negative electrodes of waste lithium batteries as claimed in claim 1, wherein: in the ball milling, the molar ratio of the waste graphite powder to the interlaminar stripping agent powder is 1: 2-6, wherein the interlaminar stripping agent is solid powder which can generate intercalation with graphite, and comprises one of ammonium chloride, ammonium carbonate, ammonium sulfate and potassium chloride.
3. The method for preparing graphene nanosheets by utilizing graphite ball milling of the negative electrode of the waste lithium battery as claimed in claim 1 or 2, wherein: in the ball milling, the ball milling time is 0.5-3 h, and the ball milling frequency is 20-30 Hz.
4. The method for preparing graphene nanoplatelets by using graphite ball milling of the negative electrodes of waste lithium batteries as claimed in claim 3, wherein: in the ball milling, the diameter of a small ball used for ball milling is 2-5 mm, and the ball material ratio is 12-18: 1.
5. the method for preparing graphene nanosheets by graphite ball milling using the negative electrodes of waste lithium batteries as claimed in any one of claims 1, 2 and 4, wherein: in the pretreatment, the times of soaking and filtering are 3 times, and the soaking time of each time is 3-4 hours.
6. The method for preparing graphene nanosheets by utilizing graphite ball milling of negative electrodes of waste lithium batteries as claimed in claim 5, wherein the method comprises the following steps: in the pretreatment, the calcination is carried out in a nitrogen atmosphere with a nitrogen flow of 100m 3 /h。
7. The method for preparing graphene nanosheets by utilizing graphite ball milling of negative electrodes of waste lithium batteries as claimed in claim 6, wherein the method comprises the following steps: in the pretreatment, the roasting temperature is 500 ℃ and the roasting time is 2 hours.
8. The method for preparing graphene nanoplatelets by graphite ball milling with the negative electrodes of waste lithium batteries as claimed in any one of claims 1, 2, 4, 6, 7, wherein: in the cleaning process, the filtrate obtained by filtering is dried, and the product obtained by processing is ammonium chloride and is used for ball milling and mixing with waste stone ink powder again to prepare the waste stone ink.
9. Graphene nanoplatelets prepared according to the process of any of claims 1 to 8.
10. Use of graphene nanoplatelets according to claim 9 for the modification of silicone rubber.
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101993065A (en) * | 2010-12-17 | 2011-03-30 | 中国科学院上海微***与信息技术研究所 | Method for preparing graphene powder |
| CN102452649A (en) * | 2010-10-18 | 2012-05-16 | 中国科学院宁波材料技术与工程研究所 | Preparation method for graphene |
| WO2017128929A1 (en) * | 2016-01-27 | 2017-08-03 | 复旦大学 | Method for preparing graphene dispersion and article thereof |
| CN111252757A (en) * | 2019-10-10 | 2020-06-09 | 中国科学院生态环境研究中心 | Method for preparing graphene by using waste lithium ion power battery |
| CN113437378A (en) * | 2021-06-17 | 2021-09-24 | 华南理工大学 | Method for recycling and reusing anode and cathode of waste battery |
| CN113942999A (en) * | 2021-10-12 | 2022-01-18 | 南京恒泰环保科技有限公司 | Method for recycling graphite from lithium battery cathode carbon powder and preparation method of graphene oxide |
-
2022
- 2022-07-20 CN CN202210855580.7A patent/CN115650216A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102452649A (en) * | 2010-10-18 | 2012-05-16 | 中国科学院宁波材料技术与工程研究所 | Preparation method for graphene |
| CN101993065A (en) * | 2010-12-17 | 2011-03-30 | 中国科学院上海微***与信息技术研究所 | Method for preparing graphene powder |
| WO2017128929A1 (en) * | 2016-01-27 | 2017-08-03 | 复旦大学 | Method for preparing graphene dispersion and article thereof |
| CN111252757A (en) * | 2019-10-10 | 2020-06-09 | 中国科学院生态环境研究中心 | Method for preparing graphene by using waste lithium ion power battery |
| CN113437378A (en) * | 2021-06-17 | 2021-09-24 | 华南理工大学 | Method for recycling and reusing anode and cathode of waste battery |
| CN113942999A (en) * | 2021-10-12 | 2022-01-18 | 南京恒泰环保科技有限公司 | Method for recycling graphite from lithium battery cathode carbon powder and preparation method of graphene oxide |
Non-Patent Citations (1)
| Title |
|---|
| 詹剑虹等: "废旧锂离子电池负极石墨闭环回收的基础研究", 电源技术, no. 2, pages 175 * |
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