Article pubs.acs.org/IECR
Cite This: Ind. Eng. Chem. Res. XXXX, XXX, XXX−XXX
An Organic/Inorganic Synergistic Electrolysis for Overcharge Protection of Electric Vehicle Batteries Fanjun Kong,† Fangtian Yu,‡,§ Wenqian Lu,† Zhengqiu Yuan,*,†,‡,§,∥,⊥ and Bin Qian† †
College of Physical and Electronic Engineering, Changshu Institute of Technology, Changshu 215500, China Department of Chemistry, University of Science and Technology of China, Hefei 230001, China § Jiangsu Chunlan Clean Energy Academy Co., Ltd., Taizhou 225300, China ∥ Jiangsu FL New Materials Co., Ltd., Changzhou 213163, China ⊥ Far East Smarter Energy Co., Ltd. (FESE), Yixing 21420, China Ind. Eng. Chem. Res. Downloaded from pubs.acs.org by IOWA STATE UNIV on 01/25/19. For personal use only.
‡
S Supporting Information *
ABSTRACT: Safety is a stumbling block to the applications of the lithium-ion batteries in electric vehicles, especially under the abuse condition of overcharge. Much research on preventing overcharge is being done to ensure the safety of the lithium-ion batteries. However, almost no strategy can balance the safety and the performance of the lithium-ion batteries well for overcharge protection. No data to support the longer term effectiveness of the used strategy were presented in the previous reports. Herein, a new electrolysis reaction, synergistic electrolysis of the organic/inorganic compounds (p-fluorotoluene and Li2CO3) is built for the first time as a controllable gas source to solve the overcharge problem of the prismatic lithium-ion battery cell with a current interrupt device inside. Overall, the balance point between the long-time performance and overcharge protection can be well achieved using the synergistic electrolysis.
■
electrolyte interface.15−19 The formed polymer film acts as a passive layer increasing internal impedance and eventually shutting down LIBs safely.15 It is also suggested that the conductive polymer film grown through the pores of the separator results in the internal short-circuit between cathode and anode to bypass the overcharging current.16 Different from the experimental research of the coin cell and even the little pouch LIBs cell (50 Ah) is much more complicated. Large heat production and poor heat dissipation performances of the big EVs cells cause the thermal-runaway to be in advance greatly. The dosage of the aromatic additives must be increased in actual application. However, the aromatic compounds deteriorate the cell performance, especially when its concentration is more than several weight percent of the electrolyte.20,21 The safety and the good performances can hardly be obtained simultaneously. Up to the present, no study has been reported on the long-time performance, such as thousands of cycles, of the EV cell using the aromatic compounds as the electrolyte additives for overcharge protection. Strategy Design for CID Overcharge Protection. Most prismatic LIBs cells adopt the external electronic circuit that interrupts surplus current by the current interrupt device
INTRODUCTION Lithium-ion batteries (LIBs) have been widely used in portable electronic devices, electric vehicles (EVs), and distributed energy storage due to their high energy density and high power density.1,2 However, they will ignite or explode especially under abuse conditions such as overcharge, excessive heating, crushing, and so on.3−6 Therefore, the safety of LIBs is an important issue for their applications. Up to the present, much research on improving thermal stability and preventing overcharge is being done to ensure the safety of LIBs.7 Overcharge protection has been one of the most critical issues of the prismatic LIBs cell. The overcharge can result in not only fire but also explosion. The inherently safe LIBs can be realized by improving electrode materials, such as dopping and coating technology for stable high capacity cathode materials. However, stability-enhanced materials often not only sacrifice performances, such as capacity, rate capability, and reliability, but also increase the process difficulty and the cost of the materials preparation.8,9 Using electrolyte additives is another way to achieve the safe LIBs. Several types of the electrolyte additives, such as redox shuttle (RS) and aromatic compounds, for overcharge protection have been reported so far. The mechanism of RS is consuming extra current by repetitive redox reaction between cathode and anode. Due to the limited transport rate, RS is ineffective against the large currents resulted from the big LIB cell with a large capacity.10−14 The aromatic compounds polymerize electrochemically at the electrode/ © XXXX American Chemical Society
Received: October 25, 2018 Revised: January 9, 2019 Accepted: January 11, 2019
A
DOI: 10.1021/acs.iecr.8b05278 Ind. Eng. Chem. Res. XXXX, XXX, XXX−XXX
Article
Industrial & Engineering Chemistry Research
Figure 1. (a) The working principle of the current interrupt device (CID), which is composed of a pressure trigger and a fuse; (b) The increasing of the inner gas pressure of the normal prismatic cell in the whole overcharge process, starting from 100% state of charge (SOC). (c) The increasing of the inner gas pressure of the special prismatic cell, using auxiliary gassing source, in the whole overcharge process.
(CID) composed of a pressure trigger and a fuse. The working principle of the CID is as follows (Figure 1a): First, the internal pressure is increasing by gas-generation in the overcharge process; Second, the internal pressure reaches the activation pressure (0.45−0.55 MPa) of the pressure trigger of CID, and the external electronic short-circuit takes place with thousands ampere transient currents. Next, the fuse is melting and the charging circuit is cut off in 2 s. Lastly, the prismatic LIBs cell is absolutely safe. This strategy has the highest reliability for overcharge protection of the LIBs. As shown in Figure 1b and c, the whole process of the overcharge thermal runaway can be divided into three stages: (1) Overcharging accompanied by heat production (slow temperature rise, green area A); (2) Overcharging with the production of a large amout of heat (rapid temperature rise, yellow area B); (3) Thermal runaway accompanied by explosion and then fire (red area C). If the amount of the generated gas is not enough before the thermal runaway, the CID does not work and the LIBs cell will explode (red curves in Figure 1b and c). Yellow curves in Figure 1b and c represent the critical condition of thermal runaway. In the normal chemical system, the green curve in Figure 1b can hardly been obtained due to the insufficient of the generated gas. The gasgeneration is of great importance to the successful implementation of the CID strategy. The following three properties are must required for the gas-generation process: (a) The gassing reaction potential is within appropriate range, 4.5−5.0 V; (b) A sufficient amount of gas should be produced before the thermal runaway to activate the pressure trigger; (c)
The gas-generation reaction can not worsen the electrochemical performance of the EVs cell in the whole service life. The green curve (see Figure 1) can be achieved using auxiliary gassing source, such as building the gas-generation reactions. Area D (see Figure 1) is the state of the cutoff of the cells. Biphenyl (BP) is a typical example of the aromatic additives for overcharging protection. BP is electrochemical oxidized to form a poly(p-phenylene)-type polymer through radical coupling mechanism accompanied by hydrogen generating.22−25 The released gas is used to activate the pressuretrigger of the CID to stop the battery overcharging at about 4.4 V (vs Li/Li+).25 However, BP often deteriorates the cell performance, especially the cycle life. It has been reported that BP significantly decreases the anode cycling efficiency due to the reaction with high active intercalated-lithium anode compounds.16,17 In addition, BP is suspected to be gradually oxidized during prolonged cycling or storage, because its onset potential is quite closed to the potential of the fully charged cathode as well as the other polyphenyl (PP) compounds.18,19 Thus, BP itself and other PP compounds are not promising additives in terms of the overcharge protection. The electrolysis gas-generation reaction including the above three properties has not been reported until now and has never been proven in further in LIBs industry. CO2 in air would inevitably alter reaction pathway and lead to the formation of parasitic products such as LiOH and Li2CO3, resulting poor cyclability and high polarization in Li− air batteries.26−30 Once the Li-ion being introduced, the charge potential quickly rises up to 4.2 V and the related discharge B
DOI: 10.1021/acs.iecr.8b05278 Ind. Eng. Chem. Res. XXXX, XXX, XXX−XXX
Article
Industrial & Engineering Chemistry Research products are converted from Li2O2 to Li2CO3, as follows: 2CO2 + O2 + 4Li+ + 4e− = 2Li2CO3 (1).30 More seriously, the resulted high polarized voltage leads to the irreversible oxidation of other key components. Amazingly, these harmful features are greatly useful on the other hand. The reverse reaction of the reaction (1), given by 2Li2CO3 = 2CO2 + O2 + 4Li+ + 4e− (2), is a gas-generation one. Futherly, the Li2CO3 is very stable to both the cathode materials and the electrolyte in LIBs. The presence of Li2CO3 in the cathode causes none of the effects detrimental to the normal operation of LIBs in principle. The reaction (2) is regarded as the perfect gasgeneration reaction for the overcharge protection in the prismatic LIBs EVs cell with the CID. However, the Li2CO3 added into the cathode may not be fully decomposed to release sufficient gas within the time limit to activate the pressuretrigger as well as that of the Li−air batteries.30 If a substance electrolysis can be found to synergistically accelerate the Li2CO3 electrolysis (an auxiliary gassing source, Figure 1c), the reaction (2) can be perfected to solve the overcharge problem of prismatic LIBs EVs cell in a limited time. Fluorinated aromatic compounds are regarded to have a higher onset oxidation potential than BP. Herein, inspired by the synergistic effect between cyclohexyl benzene (CHB) and BP,23 the p-fluorotoluene is chosen to find a new synergistic electrolysis reaction. The linear sweep voltammetry (LSV) was performed for three samples for 1 wt % Li2CO3 in the cathode (blue curve), 1 wt % p-fluorotoluene in the electrolyte (red curve), and the combination of 1 wt % Li2CO3 in the cathode and 1 wt % p-fluorotoluene in the electrolyte (hereafter called 1 wt % Li2CO3 + 1 wt % p-fluorotoluene, black curve) as shown in Figure 2a. The NCM333 cathode materials used in LSV coin cell were delithiated up to 4.5 V (vs graphite in 40Ah cell). We used the delithiated NCM333 cathode materials for the LSV study to exclude the influence of the delithiated current below 4.5 V. The oxidation current starts to increase above 4.7 V for the Li2CO3 and 4.6 V for the p-fluorotoluene (electropolymerization follows the radical coupling mechanism) samples, respectively. The oxidation current of for the base electrolyte stays negligible until 5.5 V (not shown here). Thus, the observed oxidation current is obviously due to the Li2CO3 or the p-fluorotoluene. The onset potential for 1 wt % Li2CO3 + 1 wt % p-fluorotoluene is similar to that of the pfluorotoluene, however, the oxidation current is quite large (black curve in Figure 2a). For comparison, the 1 wt % Li2CO3 + 1 wt % p-fluorotoluene current is much larger than the numeric sum of the 1 wt % Li2CO3 current and the 1 wt % pfluorotoluene current. The synergistic behavior between the Li2CO3 and the p-fluorotoluene is reported for the first time to our knowledge. The synergistic electrolysis between Li2CO3 and p-fluorotoluene is successfully used to protect the overcharge of EVs cells with different chemical systems in our work. Furtherly, the reliability of the organic/inorganic synergistic electrolysis has been validated in success by the long cyclic performance of the EVs cell. Validation of Overcharge Protection. First, we want to clarify the influence of Li2CO3 toward the overcharge of the prismatic EVs cells. The capacity of the prismatic NCM333 cell is about 40Ah, using the LiNi0.33Co0.33Mn0.33O2 as the cathode material and the artificial graphite as the anode material. Without Li2CO3 in cathode and p-fluorotoluene in electrolyte, the overcharge process of the NCM333 cell (Figure 2b) presents well coincide with the typical three stages of the thermal runaway of prismatic cell in the overcharge proposed
Figure 2. (a) The electrochemical windows of the coin cell, NCM333||1 mol L−1 LiPF6 electrolyte in EC-EMC (3:7, wt.)||Li, with 1 wt % Li2CO3 in cathode (blue curve), 1 wt % p-fluorotoluene in electrolyte (red curve), and 1 wt % Li2CO3 in cathode +1 wt % pfluorotoluene in electrolyte (black curve) employing linear sweep voltammetry (LSV) with a scan rate of 1.0 mV s−1 at the range of oxidative potential 4.0−5.5 V. (b) The voltage (black curve) and temperature (red curve) of the prismatic cell using LiNi0.33Co0.33Mn0.33O2 as cathode and artificial graphite as anode with about 40Ah, presenting the typical three stages of the overcharge thermal runaway in the whole overcharge process, A, B, and C.
above (Figure 1b). In area A, the charging voltage is increasing from 4.16 to 4.59 V. The temperature of the geometrical center of the cell surface increases from 33 to 47 °C, resulting from the anode side reactions, such as lithium plating and the slow oxidation of the electrolyte on the cathode surface. After 125% state-of-charge (SOC), the temperature is increasing faster with a constant charging voltage of 4.6 V, ascribing to the acute oxidation of the electrolyte. The overcharging cell is switching from area B to area C. At 143% SOC (overcharge time, 25.8 min), the detected temperature goes up from 89 to 250 °C in a flash, then the cell explodes immediately without the activations of the pressure-trigger and the vent (see Supporting Information (SI) Figure S1 and Figure S2a). SI Table S1 shows all the overcharge results of the prismatic NCM333 cells with different contents of the Li2CO3 (wt %) in cathode. When the Li2CO3 is added into the cathode, the overcharge processes in detail of the prismatic NCM333 cell vary significantly, as follows: (a) the maximum value of charging voltage increases from 4.6 to 4.9 V, near to the electrochemical decomposition potential of Li2CO3 (LSV blue curve in Figure 2a); (b) the obvious separates of the activation time of the pressure-trigger, the vent and the final explosion in chronological order; and (c) C
DOI: 10.1021/acs.iecr.8b05278 Ind. Eng. Chem. Res. XXXX, XXX, XXX−XXX
Article
Industrial & Engineering Chemistry Research
graphite as the anode material, is more serious. Figure 3a shows the charge voltage and the temperature increasing as the
the time of the explosion is put off until after 50 min (25.8 min, without Li2CO3). The addition of Li2CO3 does improve the overcharge protection of prismatic cells with CID, by activating the CID trigger and prolonging the explosion time, but the results of all the experiments are NG (see SI Figure S2b). Increasing the dosage of the Li2CO3 in cathode does not solve the overcharge problem radically. Because the amount of Li2CO3 to the overcharge protection exists the saturation value. On the other hand, blindly increasing the content of the Li2CO3 in cathode will sacrifice the capacity and the energy density of the cell. After p-fluorotoluene in moderation being introduced into the electrolyte, the overcharge protection of the addition of Li2CO3 in prismatic cells with CID does works. Table S2 shows the overall overcharge results of the NCM333 prismatic cells. However, when the dosage of Li2CO3 in cathode is less than 1%, no matter how much p-fluorotoluene adding, all results are NG (SI Table S2). When the content of the Li2CO3 is 1% (wt %) in the cathode, 1% (wt %) p-fluorotoluene in the electrolyte can make sure the overcharge protection of prismatic cells using CID (SI Table S2, Figure S2c). However, without p-fluorotoluene, the NCM333 prismatic cells with even more than 1% (wt %) Li2CO3 in cathode can not pass the overcharge test (SI Table S1). The results in SI Table S2 continue to show that the amount of the individual Li2CO3 to the effects of the overcharge protection exists a saturation effect. More importantly than all of that, p-fluorotoluene can enhance the overcharge protection of the Li2CO3 to the prismatic cell by accelerating the gassing reaction. The time of the CID activation (tCID trigger) in samples containing 2% (wt %) p-fluorotoluene is 2−3 min earlier than that of 1% (wt %) p-fluorotoluene, further showing the enhancement of pfluorotoluene in overcharge protection (SI Figure S2d, no vent open, absolutely safe). Compared to the low-nickel chemical system of the NCM333 cells, the NCM622 prismatic cell (50Ah), composed of LiNi0.6Co0.2Mn0.2O2 as the cathode material and the artificial graphite as the anode material, shows an earlier thermal runaway in overcharge. SI Figure S3a shows the overcharge process of NCM622 cell with both 0.8% (wt %) Li2CO3 in cathode and 2% (wt %) p-fluorotoluene in electrolyte, corresponding to the typical three stages of the thermal runaway of prismatic cell in the overcharge test. When the NCM622 cell is charged to 150% SOC (30 min), the cell explodes immediately without the activations of the pressuretrigger and the vent. Increasing the amount of Li2CO3 in cathode from 0.8% (wt %) to 1% (wt %), the overcharge protection is improved. The CID is activated (28 min) and the time of the thermal runaway is prolonged from 30 to 40 min (SI Figure S3b), although no p-fluorotoluene is added into the electrolyte. Combining 1% (wt %) Li2CO3 in the cathode and 2% (wt %) p-fluorotoluene in the electrolyte, the NCM622 prismatic cells pass the overcharge test easily (SI Figure S3c). The CID activates at 24 min (140% SOC) with the vent no open. The maximum temperature is less than 80 °C in the whole overcharge process. High voltage battery system is one of the development directions of LIBs with high energy density. The higher the cutoff voltage of charging, the more difficult the overcharge protection.31 Compared to the normal 4.2 V system, just like NCM333 and NCM622 cells mentioned above, the overcharge problem of 4.4 V NCM523 prismatic cell, which is composed of LiNi0.5Co0.2Mn0.3O2 as the cathode material and the artificial
Figure 3. Overcharge process of the 4.4 V NCM523 prismatic cell (52Ah), composed of LiNi0.5Co0.2Mn0.3O2 as cathode and artificial graphite as anode, by altering the addition amount of the Li2CO3 in cathode and p-fluorotoluene in electrolyte, respetively, (a) 1% Li2CO3 in cathode, and (c) 1% Li2CO3 in cathode and 3% p-fluorotoluene in electrolyte.
function of the SOC of the 4.4 V NCM523 prismatic cell (1%, wt %, Li2CO3 in cathode). The whole process of the thermalrunaway of 4.4 V NCM523 cell in the overcharge can also be divided into the presented three stages: area A, B and C. However, the temperature in area B goes up very fast in a short time (from 48 to 100 °C in 1.5 min), ascribing to the acute oxidation of the electrolyte on the surfaces of the high voltage cathode materials. After only 16 min (127% SOC), the 4.4 V NCM523 prismatic cell explodes in a sudden without the activations of both the CID and the vent. When adding 3% (wt %) p-fluorotoluene into the electrolyte, the 4.4 V NCM523 prismatic cell easily passes the overcharge test (Figure 3b). The overall overcharge process can be divided into only two parts: area A, and D. Owing to the Li2CO3/p-fluorotoluene synergistic electrolysis, the CID is activated in 8.5 min with a direct transition to area D. The maximum temperature in the whole process is less than 45 °C. Synergistic Electrolysis Mechanism. Based on the overcharge results of the NCM333, NCM622 and 4.4 V NCM523 cells, the electrolytic polymerization of organic pfluorotoluene through radical coupling mechanism is found to synergistically accelerate the electrolysis gassing of the D
DOI: 10.1021/acs.iecr.8b05278 Ind. Eng. Chem. Res. XXXX, XXX, XXX−XXX
Article
Industrial & Engineering Chemistry Research
close to each other (LSV in Figure 2a), the high active and ubiquitous free radicals can capture the electrons from the surfaces of Li2CO3 particles to complete the electrolysis gassing of reaction (2), see the Figure 4c. Unconstrained by the conductive touchpoints, the electrochemical polymerization of the p-fluorotoluene can greatly promotes the decomposition of Li2CO3 to produce gas, CO2 and O2. The combination of the Li2CO3 and the p-fluorotoluene is benefit for solving the overcharge problem of the prismatic cells with CID, which is ascribed to the Li2CO3/p-fluorotoluene synergistic electrolysis. The mechanism in detail is being studied and will be reported in our next work. Longer Term Effectiveness Analysis of The Synergistic Strategy. Whether the technology of the Li2CO3/pfluorotoluene synergistic electrolysis can be used in application depends on the additives not worsing the electrochemical performance of the EVs cell in the whole service life. We have checked that the capacity retentions (three parallel samples) of NCM622 prismaitc cells after 1400 cycles are 90.87% for the cell with 1% (wt %) Li2CO3 in cathode (sample A), 89.11% for the cell with 1% (wt %) Li2CO3 in cathode and 2% (wt %) pfluorotoluene in the electrolyte (sample B), and 84.02% for the cell with 1% (wt %) Li2CO3 in cathode and 4% (wt %) pfluorotoluene in the electrolyte (sample C), respectively (Figure 5a). It is worth noting that, in 500 cycles, the effect of p-fluorotoluene on the cycling performance seems negligible. However, compared to the sample A, the cycling performances of the sample B and C exhibit obvious deterioration after 500 cycles. The cycling performance of sample B is close to that of sample C at the range of between 500 and 1000 cycles. After 1000 cycles, the cycling performance of sample C with 4% (wt %) p-fluorotoluene decreases quickly, showing the deterioration of excess pfluorotoluene in electrolyte to the long-time cycling performance. The performance of sample B with 1% (wt %) Li2CO3 in cathode and 2% (wt %) p-fluorotoluene in the electrolyte can meet the practical applications of LIBs in EVs. Figure 5b shows the cycling performances of 4.4 V NCM523 prismaitc cells at 25 °C. With the adding amount of p-fluorotoluene in electrolyte increasing from 3% to 5%, the cycling performances of the 4.4 V NCM523 prismatic cells are degrading gradually (Figure 5b). The capacity retention is about 92% for the 4.4 V NCM523 cell with 1% (wt %) Li2CO3 in cathode and 3% (wt %) p-fluorotoluene in the electrolyte as well as that of the normal 4.2 V system. At the same time, the more pfluorotoluene added, the greater the direct current internal resistances (DCR), see the Figure 5c. The p-fluorotoluene may be gradually oxidized to electrochemical polymerization on the surface of the cathode materials during prolonged cycling because of the high concentration and high charging cutoff voltage, resulting in the cycling performance fading and the DCR increasing.18,19 Overall, the balance point between the long-time performance and overcharge protection can be well achieved using the strategy of the Li2CO3/p-fluorotoluene synergistic electrolysis. Compared to the fresh cell, the 1000cycled sample of 4.4 V NCM523 prismatic cell with 1% (wt %) Li2CO3 in cathode and 3% (wt %) p-fluorotoluene in the electrolyte has a better safety in overcharge test (see SI Figure S4, no vent open, and small swelling). It is suspected that a very small amout of p-fluorotoluene improve the ability of overcharge protection and the thermal stability of the cathode materials by forming a thin protective film under long-time
inorganic Li2CO3 to active the CID in a short time for LIBs overcharge protection. A possible organic/inorganic synergistic electrolysis mechanism is proposed below (Figure 4). The
Figure 4. (a) Schematic illustration of the gas-genaration in cahtode resulted from both the oxidation decomposition of electrolyte on the surface of the cathode materials and the electrochemical decomposition of Li2CO3. (b) The point-contant gassing model of the Li2CO3 electrolysis in the process of the overcharge. (c) The Li2CO3 surface-contact gassing model of the Li2CO3/p-fluorotoluene synergistic electrolysis.
generated gas is mainly resulted from both the oxidation decomposition of electrolyte on the surface of the cathode materials and the electrochemical decomposition of Li2CO3 in the overcharge (Figure 4a). However, the Li2CO3 is insulated. The electrolysis gassing reaction of Li2CO3 only happens at the touchpoints between the Li2CO3 (yellow bubble, Figure 4b) and conductive additives (e.g., conductive carbon, black bubbles, Figure 4b). The Li2CO3 point-contant gassing model sees the Figure 4b, given by the reaction (2). Due to the limitation of the reaction touchpoints, the Li2CO3 can not be fully decomposed to release sufficient gas in a short time to active the CID in pirsmatic cells. The point-contant gassing model can be used to explain the saturation effect of the Li2CO3 in the NCM333 cell (SI Table S1). Figure 4c shows the Li2CO3 surface-contant gassing model. The electrolysis gassing reaction of Li2CO3 happens not only at the conductive touchpoints, but also on its own surfaces. A large number of free radicals are produced during electrochemical polymerization of the p-fluorotoluene in electrolyte (blue part, Figure 4c), which are distributed on the surfaces of all solid particles, including the Li2CO3 particles (yellow bubbles, Figure 4c). Because the potentials of both the electrolysis of Li2CO3 and the electrochemical polymerization of the p-fluorotoluene are E
DOI: 10.1021/acs.iecr.8b05278 Ind. Eng. Chem. Res. XXXX, XXX, XXX−XXX
Article
Industrial & Engineering Chemistry Research
Inspired by the side reaction of Li−air batteries, the combination of the Li2CO3 and the p-fluorotoluene, a typical couple of the organic/inorganic synergistic electrolysis gassing, is built for the first time to solve the overcharge problem of the prismatic LIBs cells in success. The synergistic effect between the Li2CO3 in cathode and the p-fluorotoluene in electrolyte is ascribed to the oxidation decomposition of the organic intermediate free radicals to the insulated Li2CO3 on the overall surfaces of the Li2CO3 particles. The rate and content of the two additives involve a trade-off between the overcharge abuse protection and the long-time cycling performance in different chemical system. The synergistic electrolysis not only fundamentally solves the overcharge problem with no sacrificing service life but also paves the way for the discoveries of more organic/inorganic synergistic electrolysis and their related applications in energy storage, solid waste treatment, electrochemical catalysis and so on.
■
ASSOCIATED CONTENT
S Supporting Information *
The Supporting Information is available free of charge on the ACS Publications website at DOI: 10.1021/acs.iecr.8b05278. Experimental detail, overcharge data ,and phenomena of the NCM333 cells, and the overcharge process of the NCM622 prismatic cell (PDF)
■
AUTHOR INFORMATION
Corresponding Author
*E-mail:
[email protected]. ORCID
Zhengqiu Yuan: 0000-0001-9604-0856 Author Contributions
F.K., F.Y., and W.L. contributed equally. Notes
The authors declare no competing financial interest.
■
ACKNOWLEDGMENTS This work is supported by the Start-up Funds of Changshu Institute of Technology and Taizhou Key Technology R&D Program (TG201707).
■
Figure 5. (a) The cyclic performances of the NCM622 prismatic cells at the room temperature (2.8−4.2 V, 1C) with different content of the two additives, Li2CO3 in cathode and p-fluorotoluene in electrolyte. (b) The cyclic performances of the 4.4 V NCM523 prismatic cells at the room temperature (2.8−4.4 V, 1C) with different contents of the two additives, Li2CO3 in cathode and pfluorotoluene in electrolyte. (c) DC internal resistances of the fresh 4.4 V NCM523 prismatic cells of the whole SOC with different content of the two additives.
REFERENCES
(1) Whittingham, M. S. Lithium Batteries and Cathode Materials. Chem. Rev. 2004, 104, 4271−4301. (2) Balke, N.; Jesse, S.; Morozovska, A. N.; Eliseev, E.; Chung, D. W.; Kim, Y.; Adamczyk, L.; García, R. E.; Dudney, N.; Kalinin, S. V. Nanoscale Mapping of Ion Diffusion in A Lithium-ion Battery Cathode. Nat. Nanotechnol. 2010, 5, 749−754. (3) Tobishima, S.; Takei, K.; Sakurai, Y.; Yamaki, J. Lithium Ion Cell Safety. J. Power Sources 2000, 90, 188−195. (4) Wu, M. S.; Chiang, P. J.; Lin, J. C.; Jan, Y. S. Correlation between Electrochemical Characteristics and Thermal Stability of Advanced Lithium-ion Batteries in Abuse Tests-Short-Circuit Tests. Electrochim. Acta 2004, 49, 1803−1812. (5) Leising, R. A.; Palazzo, M. J.; Takeuchi, E. S.; Takeuchi, K. J. A Study of the Overcharge Reaction of Lithium-ion Batteries. J. Power Sources 2001, 97−98, 681−683. (6) Biensan, P.; Simon, B.; Pérès, J. P.; Guibert de, A.; Broussely, M.; Bodet, J. M.; Perton, F. On Safety of Lithium-ion Cells. J. Power Sources 1999, 81−82, 906−912. (7) Ma, Y. L.; Yin, G. P.; Zuo, P. J.; Tan, X. L.; Gao, Y. Z.; Shi, P. F. Phosphorous Additive for Lithium-ion Batteries. Electrochem. SolidState Lett. 2008, 11, A129−A131.
cycling conditions. It means that the longer term effectiveness of this technology is enhanced in overcharge protection.
■
CONCLUSIONS Using the external electronic circuit that interrupts surplus current by a current interrupt device (CID) composed of a pressure trigger and a fuse is one of most effective ways to prevent disastrous events during the abuse of the overcharge of LIBs in EVs. The gas-generation process inside the cell is the key step in the CID strategy, which is a balancing act, both for the long-time performance and the overcharge protection. F
DOI: 10.1021/acs.iecr.8b05278 Ind. Eng. Chem. Res. XXXX, XXX, XXX−XXX
Article
Industrial & Engineering Chemistry Research (8) Golubkov, A. W.; Fuchs, D.; Wagner, J.; Wiltsche, H.; Stangl, C.; Fauler, G.; Voitic, G.; Thaler, A.; Hacker, V. Thermal-runaway Experiments on Consumer Li-ion Batteries with Metal-oxide and Olivin-type Cathodes. RSC Adv. 2014, 4, 3633−3642. (9) Kim, J.; Ma, H.; Cha, H.; Lee, H.; Sung, J.; Seo, M.; Oh, P.; Park, M.; Cho, J. A Highly Stabilized Nickel-rich Cathode Material by Nanoscale Epitaxy Control for High-energy Lithium-ion Batteries. Energy Environ. Sci. 2018, 11, 1449−1459. (10) Adachi, M.; Tanaka, K.; Sekai, K. Aromatic Compounds as Redox Shuttle Additives for 4V Class Secondary Lithium Batteries. J. Electrochem. Soc. 1999, 146, 1256−1261. (11) Lee, D.; Lee, H.; Kim, H.; Sun, H.; Seung, D. Redox Shuttle Additives for Chemical Overcharge Protection in Lithium Ion Batteries. Korean J. Chem. Eng. 2002, 19, 645−652. (12) Chen, J.; Buhrmester, C.; Dahn, J. R. Chemical Overcharge and Overdischarge Protection for Lithium-ion Batteries. Electrochem. Solid-State Lett. 2005, 8, A59−A62. (13) Dahn, J. R.; Jiang, J.; Moshurchak, L. M.; Fleischauer, M. D.; Buhrmester, C.; Krause, J. Considerations of High Rate Overcharge Protection of LiFePO4 -based Li-ion Cells Using the Redox Shuttle Additive 2,5-diterbutyl-1,4-dimethoxyben-zene. J. Electrochem. Soc. 2005, 152, A1283−A1291. (14) Buhrmester, C.; Chen, J.; Moshurchak, L.; Jiang, J.; Wang, R. L.; Dahn, J. R. Spectro Electrochemical Studies of Redox Shuttle Overcharge Additive for LiFePO4-based Li-ion batteries. J. Electrochem. Soc. 2005, 152, A2390−A2399. (15) Feng, X.; Ai, X.; Yang, H. Possible Use of Methylbenzenes as Electrolyte Additives for Improving the Overcharge Tolerances of Liion Batteries. J. Appl. Electrochem. 2004, 34, 1199−1203. (16) Xiao, L.; Ai, X.; Cao, Y.; Yang, H. Electrochemical Behavior of Biphenyl as Polymerizable Additive for Overcharge Protection of Lithium Ion Batteries. Electrochim. Acta 2004, 49, 4189−4196. (17) Shima, K.; Ue, M.; Yamaki, Y. Effect of Vinylene Carbonate as Additive to Electrolyte for Lithium Metal Anode. J. Electrochemistry(Tokyo, Jpn.) 2003, 71, 1231−1238. (18) Tobishima, S.; Ogino, Y.; Watanabe, Y. Influence of Electrolyte Additives on Safety and Cycle Life of Rechargeable Lithium Cells. J. Appl. Electrochem. 2003, 33, 143−150. (19) Watanabe, Y.; Morimoto, H.; Tobishima, S. Electrochemical Properties of Aryladamantanes as New Overcharge Protection Compounds for Lithium Cells. J. Power Sources 2006, 154, 246−254. (20) Abe, K.; Ushigoe, Y.; Yoshitake, H.; Yoshio, M. Functional Electrolytes: Novel Type Additives for Cathode Materials, Providing High Cycleability Performance. J. Power Sources 2006, 153, 328−335. (21) Chae, B.-J.; Yim, T. Sulfonate-immobilized Artificial Cathode Electrolyte Interphases Layer on Ni-rich Cathode. J. Power Sources 2017, 360, 480−487. (22) Kvarnström, C.; Bliger, R.; Ivaska, A.; Heinze, J. Sulfonateimmobilized Artificial Cathode Electrolyte Interphases Layer on Nirich Cathode. Electrochim. Acta 1998, 43, 355−366. (23) Lee, H.; Cui, S.-Y.; Park, S.-M. Electrochemistry of Conductive Polymers: XXV. Electrochemical Preparation and Characterization of Poly ( p-phenylenes) from Biphenyl and p-Terphenyl. J. Electrochem. Soc. 2001, 148, D139−D145. (24) Lee, H.; Lee, J. H.; Ahn, S.; Kim, H.-J.; Cho, J.-J. Co-Use of Cyclohexyl Benzene and Biphenyl for Overcharge Protection of Lithium-Ion Batteries. Electrochem. Solid-State Lett. 2006, 9, A307− A310. (25) Xu, K. Nonaqueous Liquid Electrolytes for Lithium-based Rechargeable Batteries. Chem. Rev. 2004, 104, 4303−4417. (26) Bruce, P. G.; Freunberger, S. A.; Hardwick, L. J.; Tarascon, J.M. Li−O2 and Li−S Batteries with High Energy Storage. Nat. Mater. 2012, 11, 19−29. (27) Luntz, A. C.; McCloskey, B. D. Nonaqueous Li−air Batteries: A Status Report. Chem. Rev. 2014, 114, 11721−11750. (28) Lim, H. K.; Lim, H. D.; Park, K. Y.; Seo, D. H.; Gwon, H.; Hong, J.; Goddard, W. A.; Kim, H.; Kang, K. Toward A Lithium−“Air” Battery: The Effect of CO2 on the Chemistry of A Lithium−Oxygen Cell. J. Am. Chem. Soc. 2013, 135, 9733−9742.
(29) Zhang, S. S.; Xu, K.; Read, J. A Non-aqueous Electrolyte for the Operation of Li/Air Battery in Ambient Environment. J. Power Sources 2011, 196, 3906−3910. (30) Qiao, Y.; Yi, J.; Guo, S.; Sun, Y.; Wu, S.; Liu, X.; Yang, S.; He, P.; Zhou, H. Li2CO3-free Li-O2/CO2 Battery with Peroxide Discharge Product. Energy Environ. Sci. 2018, 11, 1211−1217. (31) Yu, F.; Yuan, Z.; Yang, T.; Qian, B. Contagious Degradation of A Chemically Active Surface on the Cathodes of Lithium-ion Batteries Phys. Phys. Chem. Chem. Phys. 2018, 20, 19195−19207.
G
DOI: 10.1021/acs.iecr.8b05278 Ind. Eng. Chem. Res. XXXX, XXX, XXX−XXX
