An integrated system and method for charged crushing and waste heat recovery of waste lithium-ion batteries

Abstract

The present invention discloses an integrated system and method for charged crushing and waste heat recovery of waste lithium-ion batteries. The system includes an automatic feeding machine, an automatic lithium battery SOC detection device, a computer, a charged crushing device with protective gas, a gas management device, a gas purification device, and a heat exchange device. The waste lithium-ion batteries are put into a crushing device in a low-oxygen environment and are crushed under a protective gas atmosphere. The purified protective gas is sent to the hot water generated by the heat exchange device for use as a heat source. The waste battery treatment process of the present invention simplifies the battery recycling process, avoids the problems of long time consumption and pollution caused by conventional discharging methods, directly crushes and disassembles the waste batteries in a high-flow protective gas, takes away the heat released during the disassembly process while reducing the oxygen content, avoids the risk of fire and explosion during the crushing process, and effectively utilizes the collected energy to achieve the effect of energy conservation and emission reduction.

Description

Technical Field

[0001] The present invention belongs to the field of waste battery recycling, and relates to an integrated system and method for charged crushing and waste heat recovery of waste lithium-ion batteries. Background Art

[0002] Due to advantages such as high specific energy, long life, good cycle performance, and environmental friendliness, lithium-ion batteries have been widely used in fields such as electronics, communication, and new energy vehicles. China is a major producer and consumer of lithium-ion batteries. Usually, the life of a lithium-ion battery is about 2 - 3 years, and the lithium-ion battery recycling market is huge. In terms of composition, there are various heavy metal elements and organic compounds in lithium-ion batteries. If not recycled, it will pollute the environment and affect human health. In terms of recycling value, ternary lithium batteries contain various valuable metals such as nickel, cobalt, manganese, and lithium, and their content is even higher than that in natural ores, with extremely high recycling value. Therefore, the harmless recycling and utilization of lithium-ion batteries is of great significance.

[0003] Currently, the recycling methods of lithium-ion batteries are mainly pyrometallurgy, hydrometallurgy, and biohydrometallurgy. Pyrometallurgy requires high-temperature calcination of waste batteries, with high energy consumption and the generation of a large amount of harmful waste gas, resulting in environmental pollution. Hydrometallurgy requires the use of a large amount of strong acid and alkali solutions, generating a large amount of wastewater and polluting the environment. At the same time, it involves operations such as leaching, extraction, and precipitation, with complex processes. Biohydrometallurgy uses the metabolism of microorganisms to dissolve and leach the positive electrode metal ions of lithium-ion batteries, but the microbial culture period is long and the requirements for the growth environment are high.

[0004] When recycling, it is necessary to disassemble and sort waste batteries. Waste lithium-ion batteries are rich in residual energy, and direct disassembly may cause fire and explosion. Therefore, it is necessary to discharge waste batteries. Common discharge methods include physical discharge, chemical discharge, and mechanical puncture discharge. Physical discharge uses an external circuit to release residual electricity, but the discharge speed is slow and the efficiency is low. Chemical discharge uses salt solution immersion to generate a chemical reaction and release electrical energy, but it is easy to cause electrolyte leakage and generate organic wastewater. Mechanical puncture is prone to fire and explosion, threatening the safety of operators and damaging equipment. While these discharge methods have their respective defects, they cannot utilize the residual energy in the battery, resulting in energy waste.

[0005] Currently, during the process of lithium-ion battery crushing, sorting, and recycling, the residual energy in the battery may cause fire and explosion, and at the same time, the residual energy is not utilized and wasted. These problems need to be solved urgently. Common discharge methods all have serious defects, restricting their application in production. Summary of the Invention

[0006] Aiming at the deficiencies of the existing technology, the purpose of the present invention is to provide an integrated system and method for charged crushing and waste heat recovery of waste lithium-ion batteries with high safety, environmental protection and energy recovery efficiency.

[0007] To achieve the above purpose, the present invention adopts the following technical solutions:

[0008] An integrated system for charged crushing and waste heat recovery of waste lithium-ion batteries includes an automatic feeding machine, a lithium battery SOC automatic detection device, a computer, a protective gas charged crushing device, a gas management device, a gas purification device and a heat exchange device;

[0009] The automatic feeding machine is used to supply materials to the protective gas charged crushing device. The lithium battery SOC automatic detection device is connected to the computer to detect the remaining power of the waste lithium-ion battery. The computer is used to control the operation of the automatic feeding machine according to the obtained remaining power data of the waste lithium-ion battery. The protective gas charged crushing device is a mechanical crushing device. The mechanical crushing device is connected to the gas management device through a pipeline, and the mechanical crushing device is connected to the gas purification device through a protective gas output pipeline. The gas outlet of the gas purification device is connected to the heat exchange device. The heat exchange device is respectively connected to a heat supply pipeline and a lithium bromide unit, and transfers the heat obtained by exchanging heat with the protective gas to the heat supply pipeline or the lithium bromide unit.

[0010] Further, the lithium battery SOC automatic detection device includes a lithium battery placement box and a testing machine. The lithium battery placement box is a hollow structure with both ends communicating. A positive test terminal is arranged at the upper end of the lithium battery placement box, and a negative test terminal is arranged at the lower end. Both the positive test terminal and the negative test terminal are slidably arranged on the testing machine through movable rods, and the testing machine is connected to the computer.

[0011] Further, a temperature detection device is arranged in the mechanical crushing device. The temperature detection device is connected to the computer to monitor the temperature during the crushing process, and the computer dynamically controls the feeding speed of the automatic feeding machine according to the temperature change.

[0012] Further, a gas quality detection device is arranged in the gas purification device.

[0013] Further, a temperature measuring device, a flame detection device, a water spray device and an alarm device are arranged in the mechanical crushing device. Temperature measuring devices are arranged at both the air inlet and the air outlet of the mechanical crushing device. A flow control valve is arranged at the air inlet.

[0014] An integrated method for charged crushing and waste heat recovery of waste lithium-ion batteries includes the following steps:

[0015] Step 1. Randomly sample and detect waste lithium-ion batteries using the lithium battery SOC automatic detection device. The computer calculates the detection data and sets the feeding amount and speed of the feeding machine according to the calculation results;

[0016] Step 2. Continuously introduce a high-flow protective gas into the crushing device to maintain a low-oxygen environment inside the crushing device;

[0017] Step 3. The automatic feeding machine inputs the waste lithium-ion batteries into the crushing device under the control of the computer in Step 1, and performs charged crushing in the atmosphere of the protective gas. During the crushing process, the temperature change is monitored by the temperature detection device set in the crushing device, and the feeding speed of the automatic feeding machine is dynamically controlled according to the temperature change;

[0018] Step 4. The flowing protective gas introduced into the crushing device is in full contact with the battery material being crushed, absorbs and takes away the heat generated during the battery crushing process;

[0019] Step 5. The protective gas after heat exchange is discharged from the crushing device, and then undergoes purification and drying treatment to remove dust particles, organic gas, and fluoride gas;

[0020] Step 6. The purified protective gas is sent to the heat exchange device for countercurrent heat exchange with water;

[0021] Step 7. The hot water generated by the heat exchange device after heat exchange is used as a heat source.

[0022] Further, in Step 1, the computer calculates the average value of the detection data, uses the average value of the detection data as the average remaining power of the overall waste lithium-ion batteries, then calculates the heat generation per kilogram of battery crushing according to the average remaining power, estimates the temperature rise value caused by the heat generation per kilogram of battery crushing according to the type of the crushing device, the type and flow rate of the protective gas, and finally calculates the maximum feeding speed that makes the temperature not higher than the set threshold.

[0023] Further, in Step 2, the gas inlet mode adopts pulse gas inlet; the gas flow rate is 1.59 t·h -1 to 4.7 t·h -1 between.

[0024] Further, in Step 2, the protective gas is distributed by a gas distribution pipe, and the protective gas is introduced from all around the crushing device.

[0025] Further, in Step 5, the removal method of the organic gas is activated carbon adsorption method, catalytic combustion method, catalytic oxidation method or acid-base neutralization method; the fluoride removal method is water spray, sodium hydroxide solution spray or solid alumina chemical adsorption; the gas drying method is anhydrous magnesium sulfate absorption method, activated carbon adsorption method, activated alumina absorption method or silica gel adsorption method.

[0026] The present invention has the following beneficial effects:

[0027] The present invention eliminates the discharging step. The remaining power of the waste battery is measured and estimated by the automatic detection device for the state of charge (SOC) of the lithium battery, and the temperature change caused by the heat release during crushing is monitored by the temperature detection device. The feeding speed is set according to the calculation result and dynamically controlled by the temperature detection device. The waste battery is charged and crushed in a high-flow protective gas, which reduces the oxygen content while taking away the heat generated during the crushing process and utilizes this part of the heat.

[0028] The present invention simplifies the battery recycling process and solves the problems of long time consumption and pollution caused by the conventional discharging method. The feeding speed is controlled according to the measurement and calculation results, which avoids the problem of out-of-control high temperature during the crushing process from the root cause, and further prevents fire and explosion through the protective gas. Description of the Drawings

[0029] Figure 1 is a schematic structural diagram of the integrated process system for charged crushing and waste heat recovery of the present invention

[0030] Figure 2 is a process flow chart of the integrated process for charged crushing and waste heat recovery of the present invention Detailed Embodiments

[0031] The following further elaborates on the specific content of the present invention in detail in conjunction with embodiments.

[0032] As Figure 1 shown, the integrated system for charged crushing and waste heat recovery of the waste lithium-ion battery of the present invention includes an automatic feeding machine, an automatic detection device for the state of charge (SOC) of the lithium battery, a computer, a charged crushing device with protective gas, a gas management device, a gas purification device, and a heat exchange device.

[0033] The automatic feeding machine is used to supply materials to the charged crushing device with protective gas. The automatic detection device for the state of charge (SOC) of the lithium battery is connected to the computer and sends the detected remaining power data of the waste lithium-ion battery to the computer for calculation. The computer controls the operation of the automatic feeding machine according to the calculation result. The automatic detection device for the state of charge (SOC) of the lithium battery includes a lithium battery placement box and a tester; the lithium battery placement box is a hollow structure with both ends communicating. The upper end of the lithium battery placement box is provided with a positive electrode test terminal, and the lower end is provided with a negative electrode test terminal. Both the positive electrode test terminal and the negative electrode test terminal are slidably arranged on the tester through movable rods; the tester is connected to the computer, and the tester can be set on the computer.

[0034] The protective gas charged crushing device is a mechanical crushing device. The mechanical crushing device is connected to the gas management device through a pipeline. The mechanical crushing device is connected to the gas purification device through the protective gas output pipeline. The gas outlet of the gas purification device is connected to the heat exchange device. The heat exchange device is respectively connected to the heat supply pipeline and the lithium bromide unit, and transfers the heat obtained by heat exchange to the heat supply pipeline or the lithium bromide unit. A temperature detection device is arranged in the mechanical crushing device. The temperature detection device is connected to a computer to monitor the temperature change during the crushing process. The computer simultaneously dynamically controls the feeding speed according to the temperature change. If the temperature rises significantly within a short period of time or reaches the set threshold, the feeding speed of the automatic feeding machine is reduced or the feeding is stopped through the feedback control system. After the temperature returns to normal, the original speed is restored.

[0035] The gas outlet of the heat exchange device is connected to the gas management device through a pipeline again. The protective gas after heat exchange by the heat exchange device is sent into the gas management device again for reuse.

[0036] As Figure 2 shown, the integrated method for charged crushing and waste heat recovery of waste lithium-ion batteries includes the following steps:

[0037] Step 1. Randomly sample and detect waste lithium-ion batteries using a lithium battery SOC automatic detection device, and then automatically perform program operations on the detection data through a computer connected to the detection device;

[0038] The computer calculates the average value of the detection data, uses the average value of the detection data as the average remaining power of the overall waste lithium-ion batteries, then calculates the heat generation per kilogram of battery crushing according to the average remaining power, sets the heat utilization rate to 75%, then estimates the temperature rise value caused by the heat generation per kilogram of battery crushing according to the set type of crushing device, the type and flow rate of the protective gas used, and finally calculates the maximum feeding speed that makes the temperature not higher than the set threshold.

[0039] Step 2. Introduce a high-flow protective gas into the crushing device to maintain a low-oxygen environment in the crushing device;

[0040] (1) The intake method adopts pulsed intake;

[0041] (2) The protective gas can be nitrogen, carbon dioxide, helium, argon, or any combination of these gases;

[0042] (3) The temperature of the introduced gas is room temperature, and the gas flow rate is 1.59 t·h -1 to 4.7 t·h -1 between.

[0043] Step 3. The automatic feeding machine is controlled by the computer in Step 1. According to the calculation result in Step 1, the automatic feeding machine feeds the waste lithium-ion batteries into the crushing device at the calculated feeding speed and performs charged crushing in an inert gas atmosphere to keep the temperature within a safe range during crushing.

[0044] (1) The crusher can be one of a shear crusher, a cone crusher, a jaw crusher, a hammer crusher, or an impact crusher, or any combination of any two of them;

[0045] (2) Air seals are provided at the inlet and outlet of the crushing device;

[0046] (3) A temperature measuring device, a flame detection device, a water spray device, and an alarm device are provided in the crushing device. If the temperature is higher than 150 °C or a fire breaks out, water is immediately sprayed to cool down and extinguish the fire and an alarm signal is sent;

[0047] (4) An explosion-proof film is installed on the crushing device;

[0048] (5) A sound insulation device is provided outside the crushing device;

[0049] (6) Temperature measuring devices are provided at both the inlet and outlet of the crushing device;

[0050] (7) A flow control valve is provided at the inlet.

[0051] Step 4. The inert gas is distributed by a gas distribution pipe, surrounding the crushing device for one week and being above the crusher. The flowing inert gas is in full contact with the battery material during crushing, absorbing and carrying away the heat generated during the battery crushing process.

[0052] Step 5. A temperature detection device is provided in the crushing device. The temperature detection device is connected to the computer in Step 1 to monitor the temperature change and dynamically control the feeding speed according to the temperature change. If the temperature rises significantly within a short period of time or reaches the set threshold, the feeding speed of the automatic feeding machine is reduced or feeding is stopped through the feedback control system. After the temperature returns to normal, the original speed is restored.

[0053] Step 6. The inert gas after heat exchange is discharged from the crushing device and enters the purification device to purify and remove dust particles, organic gas, and fluoride gas

[0054] (1) The method for removing dust particles can be pulse bag dust collection, bag dust collection, pulse cartridge dust collection, cyclone dust collection, or wet dust collection;

[0055] (2) The method for removing organic gas can be activated carbon adsorption, catalytic combustion, catalytic oxidation, or acid-base neutralization;

[0056] (3) The fluoride removal method can be water spraying, sodium hydroxide solution spraying, or solid alumina chemical adsorption;

[0057] (4) The gas drying methods can be anhydrous magnesium sulfate absorption, activated carbon adsorption, activated alumina absorption, or silica gel for color change;

[0058] (5) A gas quality detection device is provided in the purification device to detect whether the dust, organic matter, fluoride, and moisture content in the purified gas meet the standards.

[0059] Step 7. The purified protective gas enters the waste heat recovery device and exchanges heat with water in a countercurrent manner

[0060] (1) The heat exchange device can be a plate heat exchange device, a shell-and-tube heat exchange device, or a double-tube sheet heat exchange device;

[0061] (2) The heat-exchanged protective gas enters the gas management device for reuse;

[0062] (3) Temperature measuring devices are provided at the inlet, outlet, water inlet, and water outlet of the waste heat recovery device;

[0063] (4) A flow control valve is provided at the water inlet

[0064] (5) The water flow rate of the heat exchange device is 1.1 t·h -1 ~2.39 t·h -1 ;

[0065] (6) The inlet water temperature is 20°C to 60°C, and the outlet water temperature is 70°C to 85°C;

[0066] Step 8. The hot water generated after heat exchange can enter the heating pipeline for heating in winter, can be connected to a lithium bromide unit for refrigeration in summer, and then is fed into the water tank for reuse.

[0067] The following are specific application examples:

[0068] 1000 kg of waste lithium cobalt oxide batteries (remaining 40% capacity, utilization rate 75%, available surplus energy 90 kWh) are crushed in normal temperature nitrogen with a flow rate of 1.59 t·h-1 to obtain battery scraps; the flowing nitrogen absorbs and takes away the heat generated by battery crushing, which is 2.15×108 J·h-1, and the temperature of the flowing out nitrogen is not higher than 150°C, and it is purified in the purification device; the purified nitrogen exchanges heat with cold water, using a shell-and-tube heat exchanger, and the output power can be 32.3 kW, which is connected to a lithium bromide unit, and the COP of the lithium bromide unit is taken as 0.7, and the refrigeration power is 24.0 kW.

[0069] The parameters of the heat exchange device are as follows:

[0070] Table 1 Parameters of the heat exchange device

[0071]

[0072] Table 2 Parameters of Lithium Bromide Unit

[0073]

[0074] Taking a factory that processes 200,000 tons of lithium batteries annually as an example, it can reduce sewage discharge by 200,000 tons per year, saving 2 million yuan in water fees and sewage treatment costs; in winter, it can provide heating for a 6,210 m 2 factory building, saving 370,000 yuan in heating costs; during refrigeration, it can save 1.06 million kWh of electricity, equivalent to 1.59 million yuan in electricity costs. The total annual economic benefit is 3.96 million yuan.

Claims

1. An integrated system for charged crushing and waste heat recovery of waste lithium-ion batteries, characterized in that: It includes an automatic feeding machine, an automatic lithium battery SOC detection device, a computer, a charged protection gas crushing device, a gas management device, a gas purification device, and a heat exchange device; The automatic feeding machine is used to supply materials to the charged protection gas crushing device. The automatic lithium battery SOC detection device is connected to the computer and is used to detect the remaining power of waste lithium-ion batteries. The computer is used to control the operation of the automatic feeding machine according to the obtained remaining power data of waste lithium-ion batteries; The charged protection gas crushing device is a mechanical crushing device. The mechanical crushing device is connected to the gas management device through a pipeline. The mechanical crushing device is connected to the gas purification device through a protection gas output pipeline. The gas outlet of the gas purification device is connected to the heat exchange device. The heat exchange device is respectively connected to a heat supply pipeline and a lithium bromide unit, and transfers the heat obtained by exchanging heat with the protection gas to the heat supply pipeline or the lithium bromide unit; The computer calculates the average value of the detection data, takes the average value of the detection data as the average remaining power of the overall waste lithium-ion batteries, then calculates the heat generation per kilogram of battery crushing according to the average remaining power, sets the heat utilization rate to 75%, then estimates the temperature rise value caused by the heat generation per kilogram of battery crushing according to the set type of the crushing device, the type of the used protection gas and its flow rate, and finally calculates the maximum feeding speed that makes the temperature not higher than the set threshold; Estimate the remaining power of waste batteries through the automatic lithium battery SOC detection device and monitor the temperature change caused by crushing heat release through a temperature detection device, set the feeding speed according to the calculation result, and dynamically control it through the temperature detection device; A temperature detection device is arranged in the mechanical crushing device. The temperature detection device is connected to the computer, and the computer monitors the temperature during the crushing process. The computer dynamically controls the feeding speed of the automatic feeding machine according to the temperature change; If the temperature rises significantly within a short period of time, or the temperature reaches the set threshold, the feeding speed of the automatic feeding machine is reduced or the feeding is stopped through a feedback control system. After the temperature returns to normal, the original speed is restored; The automatic lithium battery SOC detection device includes a lithium battery placement box and a testing machine; The lithium battery placement box is a hollow structure with both ends communicating. A positive electrode test end is arranged at the upper end of the lithium battery placement box, and a negative electrode test end is arranged at the lower end. Both the positive electrode test end and the negative electrode test end are slidably arranged on the testing machine through movable rods, and the testing machine is connected to the computer.

2. The integrated system for charged crushing and waste heat recovery of waste lithium-ion batteries according to claim 1, characterized in that: A gas quality detection device is arranged in the gas purification device.

3. The integrated system for charged crushing and waste heat recovery of waste lithium-ion batteries according to claim 2, wherein: A temperature measuring device, a flame detection device, a water spray device, and an alarm device are arranged in the mechanical crushing device. Temperature measuring devices are arranged at both the air inlet and the air outlet of the mechanical crushing device; A flow control valve is arranged at the air inlet.

4. A method for integrated charged crushing and waste heat recovery of waste lithium-ion batteries based on the system of claim 3, characterized in that It includes the following steps: Step 1. Randomly sample and detect waste lithium-ion batteries using the automatic lithium battery SOC detection device. The computer calculates the detection data and sets the feeding amount and speed of the feeding machine according to the calculation result; Step 2. Continuously introduce a high-flow protection gas into the crushing device to maintain a low-oxygen environment in the crushing device; Step 3. The automatic feeding machine, controlled by the computer in Step 1, feeds the waste lithium-ion batteries into the crushing device and performs charged crushing in an inert gas atmosphere. During the crushing process, the temperature change is monitored by the temperature detection device set in the crushing device, and the feeding speed of the automatic feeding machine is dynamically controlled according to the temperature change; Step 4. The flowing inert gas introduced into the crushing device comes into full contact with the battery material being crushed, absorbs and takes away the heat generated during the battery crushing process; Step 5. The inert gas after heat exchange is discharged from the crushing device, and then undergoes purification and drying treatment to remove dust particles, organic gas and fluoride gas; Step 6. The purified inert gas is sent to the heat exchange device for countercurrent heat exchange with water; Step 7. The hot water generated by the heat exchange device after heat exchange is used as a heat source.

5. The method for integrated charged crushing and waste heat recovery of waste lithium-ion batteries according to claim 4, characterized in that: In Step 1, the computer calculates the average value of the detection data, takes the average value of the detection data as the average remaining power of the overall waste lithium-ion batteries, then calculates the heat generation per kilogram of battery crushing according to the average remaining power, estimates the temperature rise value caused by the heat generation per kilogram of battery crushing according to the type of the crushing device, the type and flow rate of the inert gas, and finally calculates the maximum feeding speed that makes the temperature not higher than the set threshold.

6. The method for integrated charged crushing and waste heat recovery of waste lithium-ion batteries according to claim 4, characterized in that: In step 2, the intake method is pulsed intake; at room temperature, the gas flow rate is 1.59 t·h -1 to 4.7 t·h -1 between.

7. The method for integrated charged crushing and waste heat recovery of waste lithium-ion batteries according to claim 4, characterized in that: In Step 2, the inert gas is distributed by a gas distribution pipe, and the inert gas is introduced from all around the crushing device.

8. The method for integrated charged crushing and waste heat recovery of waste lithium-ion batteries according to claim 4, characterized in that: In Step 5, the removal method of organic gas is activated carbon adsorption method, catalytic combustion method, catalytic oxidation method or acid-base neutralization method; the fluoride removal method is water spray, sodium hydroxide solution spray or solid alumina chemical adsorption; the gas drying method is anhydrous magnesium sulfate absorption method, activated carbon adsorption method, activated alumina absorption method or silica gel adsorption method.

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