The thermal runaway of lithium-ion batteries presents a significant threat to electric vehicles by elevating the risk of fires or explosions. Safety warnings based on special gases such as H2 and CO ...are crucial to avoid thermal runaway. However, few studies or applications regarding gas warnings in electric vehicles have been reported. In this study, H2 detection experiments were performed in a real electric vehicle battery pack, and the H2 diffusion behavior was studied. The results showed that H2 can effectively warn about battery faults. In damaged batteries, H2 may be released from the micro-cracks in the battery or the vent. While H2 was detected and the power supply was cut off, the cell surface temperature tended to decrease and thermal runaway did not occur. The installation of the detector affects the detection time. Thus, H2 diffusion simulations starting from different locations were performed, and the installation location was optimized. The results indicated that setting two detectors was optimal, and the optimized detection time (from release to detection of H2) was 60 s shorter than that before optimization. The experimental and simulation results provide an effective msethod for the early warning of thermal runaway and the installation of gas detectors in electric vehicles.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Lithium-ion batteries are widely used in scalable electrochemical energy-storage stations because of their excellent characteristics. However, safety issues seriously hinder their further development ...and promotion. This paper proposes a safety warning method based on module-space air-pressure variation to provide warnings for battery thermal runaway (TR). TR is induced by different battery faults (overcharge, overheat), and the air pressure in the module space varies during the battery venting process. To verify the effectiveness of the TR warning by air-pressure variation signal, experiments were conducted in sealed and ventilated modules. The air pressures of the sealed and ventilated module spaces for batteries under 13 A (1C) overcharge-induced TR conditions were 19.3 hPa and 3.05 hPa higher, respectively, than the corresponding air pressures under normal conditions. Under 6.5 A (0.5C) overcharge-induced TR conditions, the air pressure of the sealed module space increased by 14.43 hPa. Under overheat-induced TR conditions, the sealed module space air pressure increased by 6.52 hPa. Upon detecting an air-pressure variation signal, immediate measures such as charge stoppage effectively prevent the occurrence of battery TR. The average time interval between the warning signal and battery TR was 473 s. This research provides a new way to enhance the safety of lithium-ion battery energy-storage stations.
•A novel method of applying module space air pressure variation signal to warn battery thermal runaway is proposed.•This method is based on the principle that the air pressure in module space varies after battery venting.•According to this method, the average time interval between the warning signal and thermal runaway was 473 seconds.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
H2 and CO are regarded as effective early safety-warning gases for preventing battery thermal runaway accidents. However, heat dissipation systems and dense accumulation of batteries in ...energy-storage systems lead to complex diffusion behaviors of characteristic gases. The detector installation position significantly affects the gas detection time. We conducted a gas diffusion behavior study and proposed a detection position optimization method through experiments and simulations. The gas warning effectiveness and accuracy of the simulations were experimentally verified. The results showed that an H2 detector at the top of the cabin could warn 145 s before thermal runaway. To shorten the detection time, nearly one hundred gas diffusion simulations were performed. The detector installation strategy was explored using integer programming; the results showed that installing 3–5 detectors in the cabin was optimal. The detection time with three detectors was 116.43 s shorter than with one detector. The experimental and simulation results indicate an effective gas detector installation method for early safety warnings in energy-storage cabins.
•The effectiveness of TR warning based on H2 in the energy storage cabin is studied.•The simulation model of gas diffusion in the energy storage cabin is established and validated.•The gas diffusion behavior is analyzed based on the experimental and simulation.•The optimization method of gas detector installation is proposed.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Ammonia (NH3) is one of the most frequently produced chemical products in the world, and it plays an indispensable role in life on Earth. However, its synthesis by the Haber–Bosch (H–B) process is ...highly energy intensive, resulting in extensive carbon emissions that are unsustainable due to their ability to harm the environment. Herein, we propose a facile and mass-producible strategy for increasing the rate and efficiency of nitrogen fixation through the use of copper particle-catalyzed Li nitridation and a solid electrolyte as a medium to reduce Li salt; the above strategy results in the conversion of water and nitrogen into NH3 through the use of renewable electrical energy at room temperature and atmospheric pressure. Copper particles are uniformly pressed into Li metal by a simple rolling method, and their critical role in accelerating the nitrogen fixation process is revealed by both electrochemical tests and simulations. The nitridation of the Li in the composite is reduced to a few minutes instead of the more than 40 h that are needed for bare Li and N2 at room temperature and atmospheric pressure. Our new method provides three important advantages over the H–B method: (1) the new method can be operated at atmospheric pressure, thereby lowering equipment requirements and increasing security; (2) the use of water instead of fossil fuels as a hydrogen source decreases the consumption of these fuels and the emission of CO2; and (3) the low equipment requirements lead to the ready miniaturization and decentralization of the NH3 synthesizing process, thus promoting the possible use of renewable sources of electricity (e.g., wind or solar energy).
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IJS, KILJ, NUK, PNG, UL, UM
Installing an electric-controlled pressure relief valve with battery fault detection capability on a liquid-cooled battery pack can prevent explosions caused by thermal runaway.
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The ...liquid-cooled battery energy storage system (LCBESS) has gained significant attention due to its superior thermal management capacity. However, liquid-cooled battery pack (LCBP) usually has a high sealing level above IP65, which can trap flammable and explosive gases from battery thermal runaway and cause explosions. This poses serious safety risks and challenges for LCBESS. In this study, we tested overcharged battery inside a commercial LCBP and found that the conventionally mechanical pressure relief valve (PRV) on the LCBP had a delayed response and low-pressure relief efficiency. A realistic 20-foot model of an energy storage cabin was constructed using the Flacs finite element simulation software. Comparative studies were conducted to evaluate the pressure relief efficiency and the influence on neighboring battery packs in case of internal explosions, considering different sizes and installation positions of the PRV. Here, a newly developed electric-controlled PRV integrated with battery fault detection is introduced, capable of starting within 50 ms of the battery safety valve opening. Furthermore, the PRV was integrated with the battery management system and changed the battery charging and discharging strategy after the PRV was opened. Experimental tests confirmed the efficacy of this method in preventing explosions. This paper addresses the safety concerns associated with LCBPs and proposes an effective solution for explosion relief.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Abstract
In recent years, with the continuous promulgation of relevant national energy storage strategies and policies and the rapid development of electrochemical energy storage technology, energy ...storage systems are being used more and more widely in power grids. Lithium-ion batteries have become the main battery for energy storage system applications by virtue of their high energy density, high cycle times, low self-discharge rate and low environmental pollution. In grid energy storage applications, it is often necessary to connect a large number of batteries in series and parallel to meet capacity and voltage requirements, which can lead to the amplification of very small differences in parameters between individual batteries and accumulate during charging and discharging work, eventually causing a decrease in the energy efficiency of the battery pack, a decrease in service life, and even explosive accidents. The equalization technology can well improve the imbalance problem caused by the inconsistent performance parameters between single cells, and has become a hot spot for research in recent years. In this paper, based on the analysis of battery characteristics and the characteristics of energy storage applications, we design an equalization current algorithm for battery pack under charging and discharging conditions, and design a bi-directional equalization circuit for single battery equalization, and use a modular structure and combine the current equalization algorithm to give a design scheme for a series battery pack equalization system.
Although Li-ion batteries (LIBs) are widely used, recent catastrophic accidents have seriously hindered their widespread application. In this study, a novel acoustic-signal-based battery fault ...warning and location method is proposed. This method requires only four acoustic sensors at the corners of the energy storage cabin. It captures the venting acoustic signal when a fault occurs in the cell and calculates the spatial location of the cell. The maximum spatial error is 0.1 m. Considering that the effective range of a fire-fighting facility is significantly greater than 0.1 m, such a location error is acceptable. Furthermore, a wavelet-transform-based anti-misjudgment method that ensures the reliability of the fault warning and location is proposed. Thus, a nonintrusive, timely, and effective solution to ensure the safety of the battery energy storage system (BESS) is provided.
Recycling lithium from spent batteries is challenging because of problems with poor purity and contamination. Here, we propose a green and sustainable lithium recovery strategy for spent batteries ...containing LiFePO
4
, LiCoO
2
, and LiNi
0.5
Co
0.2
Mn
0.3
O
2
electrodes. Our proposed configuration of “lithium-rich electrode || LLZTO@LiTFSI+P3HT || LiOH” system achieves double-side and roll-to-roll recycling of lithium-containing electrode without destroying its integrity. The LiTFSI+P3HT-modified LLZTO membrane also solves the H
+
/Li
+
exchange problem and realizes a waterproof protection of bare LLZTO in the aqueous working environment. On the basis of these advantages, our system shows high Li selectivity (97%) and excellent Faradaic efficiency (≥97%), achieving high-purity (99%) LiOH along with the production of H
2
. The Li extraction processes for spent LiFePO
4
, LiNi
0.5
Co
0.2
Mn
0.3
O
2
, and LiCoO
2
batteries is shown to be economically feasible. Therefore, this study provides a previously unexplored technology with low energy consumption as well as high economic and environmental benefits to realize sustainable lithium recycling from spent batteries.
The P3HT-modified LLZTO ceramic electrolyte enables high-purity lithium recycling from various spent batteries.
Garnet electrolytes, possessing high ionic conductivity (10−4–10−3 S cm−1 at room temperature) and excellent chemical/electrochemical compatibility with lithium metal, are expected to be used in ...solid‐state lithium metal batteries. However, the poor solid–solid interfacial contact between lithium and garnet leads to high interfacial resistance, reducing the battery power capability and cyclability. Garnet electrolytes are commonly believed to be intrinsically lithiophilic, and lithiophobic Li2CO3 on the garnet surface accounted for the poor interfacial contact. Here, it is proposed that the interfacial lithiophobicity/lithiophilicity of garnets (LLZO, LLZTO) can be transformed above a temperature of ≈380 °C. This transition mechanism is also suitable for other materials such as Li2CO3, Li2O, stainless steel, and Al2O3. By using this transition mechanism, uniform and even lithium can be strongly bonded no‐surface‐treated garnet electrolytes with various shapes. The Li–LLZTO interfacial resistance can be reduced to ≈3.6 Ω cm2 and sustainably withstood lithium extraction and insertion for up to 2000 h at 100 µA cm−2. This high‐temperature lithiophobicity/lithiophilicity transition mechanism can help improve the understanding of lithium–garnet interfaces and build practical lithium–garnet solid–solid interfaces.
This work reports a simple method for enhancing the solid–solid contact between garnet electrolytes (LLZTO, LLZO) and lithium metal and elucidates the lithiophobicity/lithiophilicity transition mechanism of garnets and various substrates (Li2O, Li2CO3, Al2O3) affected by molten lithium temperature, which can improve their awareness of lithium–garnet interfaces and help to build practical interfaces for solid‐state lithium metal batteries.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
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