Monthly Archives: March 2023

Environmental pollution, Lithium-ion battery

Carbon footprint of lithium-ion battery production

Leave a comment

Despite the problems lithium-ion batteries (LIBs) pose, their demand is still increasing. With the mass production of LIBs increasing globally, total greenhouse gas (GHGs) emissions from the production of LIBs are also rising rapidly. The mining of raw materials, production process and recycling process at the battery’s end-of-life release substantial amounts of GHGs. 

As the demand for LIBs is expected to rise by over 500% by 2030 (Kaunda, 2020), it is no surprise that the demand for minerals to produce LIBs such as lithium and nickel is expected to rise exponentially as well. Beaudet et al., 2020 (2020) estimate that the demand for lithium and nickel is expected to rise by over 575% and 1237% respectively in the decade. Besides the adverse environmental impact mining brings to the environment and local population as mentioned in the earlier blogs, mining itself is an emitter of GHGs. Today, global mining accounts for 4-7% of GHG emissions and this percentage is expected to increase further when global mass production of LIBs gains momentum (Henderson, 2020) (Figure 1). 

Figure 1: Lithium mine (Battery Industry, 2022)

Moving from raw materials to factories, the processes involved in the manufacturing of LIBs are also great emitters of GHGs. The production of a LIB is not a simple one, lasting from weeks to months depending on the type of batteries produced (EPEC, n.d.; Liu et al., 2021). The highly specific conditions during each phase of the production process also require high amounts of energy to sustain. Dry rooms, high temperatures and high-pressure equipment are all large electricity consumers (Liu et al., 2021) (Figure 2, 3).

Figure 2: General manufacturing process of LIBs (Liu et al., 2021)

Figure 3: Energy consumption of LIB manufacturing processes (Liu et al., 2021)

From Figure 3, we need 13.28 kWh of energy to produce a cell after summing the total energy consumption per cell of all the processes. Depending on the source of this energy comes from, the carbon dioxide emitted differs significantly (EIA, n.d.) (Figure 4). 

Figure 4: U.S. electricity net generation and resulting CO2 emissions by fuel in 2021 (EIA, n.d.)

Carbon emissions from LIB production will be significantly reduced should the majority of electricity be generated from renewable sources of energy. However, the global energy grid is still dominated by fossil fuels and coal, the most polluting fossil fuel (ClientEarth Communications, 2022). The largest GHG emitters today, China, the USA and India still rely heavily on fossil fuels particularly coal for China and India (World Population Review, 2023). In the US, fossil fuels are still responsible for over 60% of electricity generated (EIA, 2023), while coal alone still accounts for over 75% of electricity generated in India (Ministry of Coal, 2023). Despite the rapid development of renewables in China in recent years, coal still accounts for 55% of the energy generated in China (EIA, 2022). Therefore, without a significant change in the energy mix allowing renewables to dominate electricity production, the production of LIBs will without question become a great contributor to GHG emissions. 

 

Reference List

Battery Industry. (2022, June 3). Advance Lithium provides an update on mining law changes. BatteryIndustry.tech. https://batteryindustry.tech/advance-lithium-provides-an-update-on-mining-law-changes/ 

Beaudet, A., Larouche, F., Amouzegar, K., Bouchard, P., & Zaghib, K. (2020). Key Challenges and Opportunities for Recycling Electric Vehicle Battery Materials. Sustainability, 12(14), 5837. https://doi.org/10.3390/su12145837 

ClientEarth Communications. (2022, February 18). Fossil fuels and climate change: the facts. ClientEarth. https://www.clientearth.org/latest/latest-updates/stories/fossil-fuels-and-climate-change-the-facts/#:~:text=Coal%20is%20a%20fossil%20fuel,the%20world%27s%20total%20carbon%20emissions 

EIA. (n.d.). Frequently Asked Questions (FAQs) – U.S. Energy Information Administration (EIA). US Energy Information Administration. https://www.eia.gov/tools/faqs/faq.php?id=74&t=11 

EIA. (2022, August 8). International – U.S. Energy Information Administration (EIA). US Energy Information Administration. https://www.eia.gov/international/analysis/country/CHN 

EIA. (2023). Frequently Asked Questions (FAQs) – U.S. Energy Information Administration (EIA). US Energy Information Administration. https://www.eia.gov/tools/faqs/faq.php?id=427&t=3 

EPEC. (n.d.). Battery Pack Development Timeline – Prototypes to Product Production. EPEC Engineered Technologies. https://www.epectec.com/batteries/development-timeline.html#:~:text=This%20process%20can%20range%20from,material%20and%20battery%20cell%20availability 

Henderson, K. (2020, August 27). Here’s how the mining industry can respond to climate change. McKinsey & Company. https://www.mckinsey.com/capabilities/sustainability/our-insights/sustainability-blog/here-is-how-the-mining-industry-can-respond-to-climate-change 

Kaunda, R. B. (2020). Potential environmental impacts of lithium mining. Journal of Energy and Natural Resources Law, 38(3), 237–244. https://doi.org/10.1080/02646811.2020.1754596 

Liu, Y., Zhang, R., Wang, J., & Wang, Y. (2021). Current and future lithium-ion battery manufacturing. IScience, 24(4), 102332. https://doi.org/10.1016/j.isci.2021.102332 

Ministry of Coal. (2023). Generation of Thermal Power from Raw Coal. https://coal.nic.in/en/major-statistics/generation-of-thermal-power-from-raw-coal 

World Population Review. (2023). Greenhouse Gas Emissions by Country 2023. https://worldpopulationreview.com/country-rankings/greenhouse-gas-emissions-by-country 

Environmental pollution, Lithium Pollution, Pollution, SO2, Toxic Gases

Toxic gases released during the burning of Lithium-ion batteries (SO2)

Leave a comment

The third toxic gas I will be discussing is sulfur dioxide (SO2), a colourless but odorous gas that is highly toxic (United States Environmental Protection Agency, 2023). It is most commonly produced from the burning of fossil fuels and by the smelting of sulfur-containing mineral ores (Queensland Government, 2017). Naturally, erupting volcanoes are a significant source of SO2 emissions (Queensland Government, 2017). Similar to HF discussed in blog 11, SO2 is much more toxic compared to other gases released during the burning of lithium-ion batteries (LIBs) (Peng et al., 2020). 

Within batteries, SO2 is produced from burning sulfur-based compounds which are commonly used as reduction-type additives (Peng et al., 2020; Zhang, 2006). Similar to other toxic gases released during the burning of LIBs, the concentration of SO2 released depends on the state of charge (SOC) of the battery (Peng et al., 2020). The higher the SOC, the higher the concentration of SO2 released (Peng et al., 2020) (Figure 1). Despite, a lower concentration at lower SOCs, SO2 continues to make up a large part of all the toxic gases released regardless of SOC (Peng et al., 2020). While the maximum concentration of SO2 released, 115 mg/m3 (around 43.89 ppm), does not pose an immediate threat to the survival of a person, this concentration is more than enough to cause, mucositis, irritation to mucous membranes (Peng et al., 2020; Cleveland Clinic, 2022 ). 

According to Queensland Government (2017), the recommended air quality standards for sulfur dioxide are:

  • 0.20 ppm for a 1-hour exposure period
  • 0.08ppm for a 24-hour exposure period
  • 0.02ppm for an annual exposure period.

Health impacts of high concentrations of SO2:

  1. Respiratory problems
  • Difficulty to breath, people with existing respiratory problems such as asthma, and young children are particularly sensitive to the impacts of inhaling SO2. 
  • People with existing heart problems and diseases are also much more sensitive to the effects of SO2. 

2. Painful sores in the mouth/ gastrointestinal symptoms

  • High concentrations of SO2 will result in soreness in the mouth due to mucositis. Coughing and throat irritation are common symptoms related to high exposure to SO2 as well. 

(United States Environmental Protection Agency, 2023; Queensland Government, 2017)

Besides the direct impacts of SO2, SO2 can react with other chemicals in the atmosphere to form small particles that can easily enter the lungs of a person causing adverse health impacts (Queensland Government, 2017). For instance, reactions between SO2 and NOx form sulfates, which form fine particles (He et al., 2015). These fine particles are often the main culprit behind haze in parts of the world (He et al., 2015). They were also the main cause of the major haze events in Beijing-Tianjin-Hebei regions in China in 2013 (He et al., 2015). 

Figure 1: Haze event in Beijing in 2013 (Branigan, 2013)

Reference List

Branigan, T. (2013, January 14). Beijing smog continues as Chinese state media urge more action. The Guardian. https://www.theguardian.com/world/2013/jan/14/beijing-smog-continues-media-action 

Cleveland Clinic. (2022). Mucositis: Types, Symptoms & Treatment. https://my.clevelandclinic.org/health/diseases/24181-mucositis#:~:text=Mucositis%20is%20inflammation%20of%20the,painful%20and%20carries%20certain%20risks 

He, H., Wang, X., Ma, Q., Ma, J., Chu, B., Ji, D., Tang, G., Liu, C., Zhang, H., & Hao, J. (2015). Mineral dust and NOx promote the conversion of SO2 to sulfate in heavy pollution days. Scientific Reports, 4(1). https://doi.org/10.1038/srep04172 

Peng, Y., Yang, L., Ju, X., Liao, B., Ye, K., Li, L., Cao, B., & Ni, Y. (2020). A comprehensive investigation on the thermal and toxic hazards of large format lithium-ion batteries with LiFePO4 cathode. Journal of Hazardous Materials, 381, 120916. https://doi.org/10.1016/j.jhazmat.2019.120916 

Queensland Government. (2017, March 27). Sulfur dioxide. Environment, Land and Water | Queensland Government. https://www.qld.gov.au/environment/management/monitoring/air/air-pollution/pollutants/sulfur-dioxide#:~:text=Sulfur%20dioxide%20affects%20the%20respiratory,as%20asthma%20and%20chronic%20bronchitis 

United States Environmental Protection Agency. (2023, February 16). Sulfur Dioxide Basics | US EPA. US EPA. https://www.epa.gov/so2-pollution/sulfur-dioxide-basics 

Zhang, S. (2006). A review on electrolyte additives for lithium-ion batteries. Journal of Power Sources, 162(2), 1379–1394. https://doi.org/10.1016/j.jpowsour.2006.07.074

CO and CO2, Electric Vehicles, Environmental pollution, Lithium-ion battery, Toxic gases

Toxic gases released during the burning of Lithium-ion batteries (CO and CO2)

Leave a comment

Similar to hydrogen fluoride (HF), carbon monoxide (CO) and carbon dioxide (CO2) are common toxic gases that are released in the burning of LIB (Peng et al., 2020 ). CO is one of the two asphyxiant gas in ISO 13571 (Peng et al., 2020). 

ISO 13571:2012 establishes procedures to evaluate the life-threatening components of fire hazard analysis in terms of the status of exposed human subjects at discrete time intervals. – (International Organization for Standardization, 2020)

What is an asphyxiant gas?

Asphyxiant gas is a gas that results in hypoxia, the decrease of oxygen level in body tissue (Cleveland Clinic, 2022), by disarranging oxygen in the respiratory system (Gold, 2022). Besides hypoxia, asphyxiant gases will also cause ischaemia and metabolic acidosis (Gold, 2022; Cowled, 2011). Ischaemia causes deficiencies in blood oxygen, glucose and other substances (Cowled, 2011). When the supply of blood is lower than the demand, the body is no longer able to support essential normal functions (Cowled, 2011). The decrease in blood oxygen and other key substances deranges metabolic function which plays a crucial role in converting food and water into energy in the body (Cowled, 2011; Schoeller & Fjeld, 1991). On the other hand, metabolic acidosis is the buildup of acid in the body when the kidney is unable to remove enough acid in time due to failure (Gold, 2022). 

Symptoms:

  • Headaches, vomiting, lethargy, confusion
  • Loss of appetite 
  • Chest pain
  • Shortness of breath 
  • Fast heart rate
  • Loss of consciousness
  • Cardiac arrest

(Gold, 2022)

The symptoms a person suffers from by inhaling CO vary according to the concentration of CO and the duration they are exposed to. Furthermore, the deleterious effects of CO can be amplified when CO2 is breathed in with CO (Peng et al., 2020). As both of these gases are produced in conjunction with the burning of batteries, the effects of CO will be intensified. 

According to CO2 Meter (2023), the duration before CO takes effect significantly reduces when the concentration of CO exceeds 200 ppm (Figure 1). 

Figure 1: Carbon monoxide levels chart (CO2 Meter, 2023)

Burning behaviours of a 68 Ah battery (Figure 2) was studied by Peng et al. (2020) at different state of charge (SOC) and the concentration of CO and CO2 released over time was studied (Figure 3). 

Figure 2: 68 Ah lithium iron phosphate battery (Peng et al., 2020)

Figure 3: Experimental setup (Peng et al., 2020)

Batteries at a higher SOC produced the maximum CO and CO2 in the shortest duration after the battery started burning (Peng et al., 2020) (Figure 4). CO production reached a maximum of 258 ppm for 100% SOC albeit for a very short duration (Peng et al., 2020). 

Figure 4: Graphs of CO and CO2 production (Peng et al., 2020)

Although this concentration of CO will not have immediate health impacts when exposed to such a short period of time (Figure 1), we must bear in mind that this experiment used a 68 Ah battery with a nominal voltage of 3.22 V (Peng et al., 2020). According to E.ON, (n.d.), the battery capacity of an electric car (EV) is around 40 kWh with some going as high as 100 kWh and the common voltage of the batteries are 280 V and 360 V (Matsusada Precision Inc., 2019). A battery with a capacity of  40 kWh and voltage of 280 V will have a current of 143 Ah, more than double the current of the battery used in the experiment. Burning this battery will most likely increase the concentration of CO and CO2 produced to a lethal concentration that is fatal within minutes of exposure (Figure 1). 

 

Reference List

Cleveland Clinic. (2022). Hypoxia: Causes, Symptoms, Tests, Diagnosis & Treatment. https://my.clevelandclinic.org/health/diseases/23063-hypoxia#:~:text=Hypoxia%20is%20low%20levels%20of,Hypoxia%20can%20be%20life%2Dthreatening 

CO2 Meter. (2023, January 23). Carbon Monoxide Levels Chart. https://www.co2meter.com/blogs/news/carbon-monoxide-levels-chart 

Cowled, P. (2011). Pathophysiology of Reperfusion Injury. Mechanisms of Vascular Disease – NCBI Bookshelf. https://www.ncbi.nlm.nih.gov/books/NBK534267/#:~:text=Ischaemia%20occurs%20when%20the%20blood,begin%20during%20this%20ischaemic%20phase 

E.ON. (n.d.). Electric vehicles | Battery | Capacity and Lifespan. https://www.eonenergy.com/electric-vehicle-charging/costs-and-benefits/battery-capacity-and-lifespan.html#:~:text=The%20average%20capacity%20is%20around,higher%20the%20kWh%20the%20better 

Gold, A. (2022, September 26). EMS Asphyxiation And Other Gas And Fire Hazards. StatPearls – NCBI Bookshelf. https://www.ncbi.nlm.nih.gov/books/NBK519487/ 

International Organization for Standardization. (2020). ISO 13571:2012. ISO. https://www.iso.org/standard/56172.html 

Matsusada Precision Inc. (2019, June 4). Power Supply and Voltage of EV Motor | Tech | Matsusada Precision. Matsusada Precision. https://www.matsusada.com/column/ev-power.html#:~:text=Lithium%2Dion%20batteries%20are%20the,connected%20in%20series%20and%20parallel 

Peng, Y., Yang, L., Ju, X., Liao, B., Ye, K., Li, L., Cao, B., & Ni, Y. (2020). A comprehensive investigation on the thermal and toxic hazards of large format lithium-ion batteries with LiFePO4 cathode. Journal of Hazardous Materials, 381, 120916. https://doi.org/10.1016/j.jhazmat.2019.120916 

Schoeller, D. A., & Fjeld, C. R. (1991). Human Energy Metabolism: What Have We Learned from the Doubly Labeled Water Method? Annual Review of Nutrition, 11(1), 355–373. https://doi.org/10.1146/annurev.nu.11.070191.002035 

Environmental pollution, HF, Pollution, Toxic Gases

Toxic gases released during the burning of Lithium-ion batteries (HF)

Leave a comment

The first gas that we will be discussing in detail is hydrogen fluoride (HF). HF is a colourless gas which readily dissolves in water to form hydrofluoric acid (HFA) (Marx et al., 2005; Gad & Sullivan, 2014). HF is an extremely toxic gas and HFA is one of the strongest existing acids (Marx et al., 2005). 

Ingestions of more than 20 mg/kg body weight are considered a lethal dose. – Marx et al., 2005

Adverse health impacts will arise when exposed to it either in gaseous or liquid form (Centers for Disease Control and Prevention, 2018). 

Immediate signs and symptoms of exposure to HF/HFA:

  • Exposure to HFA: severe pain on exposed skin immediately or more often several hours after exposure despite no physical burns observed.
  • Ingestion of HFA: small amount of highly concentrated HF can severely damage internal organs and may even be fatal.
  • Exposure to HF gas: at low concentrations will result in eye, nose and respiratory irritation. At high concentrations, it may be fatal due to the accumulation of fluid in the lungs or cardiac arrhythmia.

Long-term impacts of short contact with HF/HFA: 

  • Survivors of inhalation of HF often suffer from chronic lung disease.
  • Survivors may suffer from permanent visual problems and damage.

(Centers for Disease Control and Prevention, 2018)

Immediate intensive care treatment is required when exposed to HF/HFA. The damage of HF/HFA to the body can continue for weeks and will have lasting impacts on the person’s health (Centers for Disease Control and Prevention, 2018; Gad & Sullivan, 2014). 

HF is one of the main toxic gas released from the combustion of batteries (refer to chemical equations in the previous blog). Although many studies about the combustion of batteries and toxic gas release have been done, few have released exact amounts of HF gases produced when a battery burns (Larsson et al., 2017). Additionally, as the different battery manufacturers and battery types contain different variations of chemical compositions, it is difficult to specify the exact amount of HF gas released for a battery with a certain capacity (Larsson et al., 2017) (Figure 1). Generally, pouch cells tend to produce the highest concentrations of HF (Larsson et al., 2017). 

[A] possible explanation would be that hard prismatic and cylindrical cells can build a higher pressure before bursting, rapidly releasing a high amount of gases/vapours from the electrolyte. Due to the high velocity of the release and thus the short reaction time, combustion reactions might be incomplete and less reaction products might be produced. – Larsson et al., 2017

Figure 1: HF released during the burning of 7 different types of batteries at different SOC (Larsson et al., 2017)

From the experiments conducted by Larsson et al. (2017), they also found that the state of charge (SOC) of a battery will also affect the rate of HF released when the battery burns. Batteries at 100% SOC tend to have more extreme heat release and flames (Larsson et al., 2017). Experiments conducted on the same type of battery also found a clear correlation between the SOC of the battery and the rate of HF produced over time (Larsson et al., 2017; Zhang et al., 2022) (Figure 2). Similar experiments on different types of cells conducted showed similar results (Larsson et al., 2017). 

Figure 2: Correlation between the rate of heat release and concentration of HF over time at different SOC (Larsson et al., 2017)

 

Reference List

Centers for Disease Control and Prevention. (2018, April 4). CDC | Facts About Hydrogen Fluoride (Hydrofluoric Acid). CDC. https://emergency.cdc.gov/agent/hydrofluoricacid/basics/facts.asp 

Gad, S., & Sullivan, D. (2014). Hydrofluoric Acid. Encyclopedia of Toxicology, 964–966. https://doi.org/10.1016/b978-0-12-386454-3.00853-8 

Larsson, F., Andersson, P., Blomqvist, P., & Mellander, B. E. (2017). Toxic fluoride gas emissions from lithium-ion battery fires. Scientific Reports, 7(1). https://doi.org/10.1038/s41598-017-09784-z 

Marx, C., Trautmann, S., Halank, M., & Weise, M. (2005). Lethal intoxication with hydrofluoric acid. Critical Care, 9(Suppl 1), P407 (2005). https://doi.org/10.1186/cc3470 

Zhang, L., Duan, Q., Meng, X., Jin, K., Xu, J., Sun, J., & Wang, Q. (2022). Experimental investigation on intermittent spray cooling and toxic hazards of lithium-ion battery thermal runaway. Energy Conversion and Management, 252, 115091. https://doi.org/10.1016/j.enconman.2021.115091 

Electric Vehicles, Environmental pollution, Lithium-ion battery, Pollution, Toxic gases

Toxic gases released during the burning of Lithium-ion batteries

Leave a comment

Today, lithium-ion batteries (LIB)/ grid-scale battery storage is one of the fastest-growing energy storage systems globally with China, US and Europe leading the market (Schoenfisch & Dasgupta, 2022) (Figure 1). Although the global economy plunged in 2020 due to the COVID pandemic, the battery market continued to grow exponentially. Between 2020 and 2021, the grid-scale battery storage market saw an annual increase of over 60% in global storage capacity (Schoenfisch & Dasgupta, 2022). 

Figure 1: Annual grid-scale battery storage additions and distribution (Schoenfisch & Dasgupta, 2022)

In spite of the rapid growth in grid-scale battery storage, the global capacity remains undesirably low should we want to reach a net zero scenario. To meet the goal, Schoenfisch & Dasgupta (2022) estimate that the global grid-scale battery storage capacity will have to increase to 680 GW by 2030 (Figure 2). 

Figure 2: Required annual increase of gird-scale battery storage to meet the net zero scenario (Schoenfisch & Dasgupta, 2022)

Although LIB is an excellent alternative and direction towards a low-carbon future, the gaps and problems these batteries continue to plague the industry. The most pressing problem these batteries have today is their sensitivity to high temperatures and susceptibility to burn (Ghiji et al., 2020) (Figure 3). There are a few ways a LIB can be ignited, they include short-circuit, overcharging, exposure to high temperature, mechanical stress and more (Larsson et al., 2017). The hazardous nature of these batteries is particularly risky when used in vehicles such as electrical vehicles and aeroplanes (Ghiji et al., 2020). 

Figure 3: Electric car on fire (Ghoshal, 2021)

According to Larsson et al. (2017), the electrolyte of LIBs often contains lithium hexafluorophosphate (LiPF6) or other Li-salts containing fluorine, which are highly flammable and reactive compounds (Guo et al., 2020). Furthermore, fluorine is commonly found in other parts of the LIB in components such as fire retardants and electrodes (Larsson et al., 2017). Being one of the lightest and most reactive metals, this makes LIBs extremely vulnerable to high temperatures and combustion. 

Besides the immediate thermal damage from burning, LIBs also release toxic gases such as carbon monoxide (CO) and hydrogen fluoride (HF) (Zhang et al., 2022). The decomposition of LiPF6 is further exacerbated when water is used as an extinguisher (Larsson et al., 2017). 

LiPF6  → LiF + PF5 – (1)

PF5 + H2O + → POF3 + 2HF – (2)

LiPF6 + H2O → LiF + POF3 + 2HF – (3)

Additionally, the composition of toxic gases released between different batteries varies according to the particular chemical composition and state of charge (SOC) of each battery (Larsson et al., 2017). The volume and threat of toxic gases released are also larger for bigger cell packs (Larsson et al., 2017). When a large amount of electrolyte evaporates when batteries are heated, this gas may not ignite immediately when released but may accumulate and result in gas explosions at later stages (Larsson et al., 2017). 

In the coming blogs, I will explore the toxic gases produced from the combustion of LIBs in detail so stay tuned for more!

 

Reference List

Ghiji, M., Novozhilov, V., Moinuddin, K., Joseph, P., Burch, I. A., Suendermann, B., & Gamble, G. (2020). A Review of Lithium-Ion Battery Fire Suppression. Energies, 13(19), 5117. https://doi.org/10.3390/en13195117 

Ghoshal, A. (2021, December 15). How Lithium Ion batteries in EVs catch fire – Adreesh Ghoshal – Medium. Medium. https://adreesh-ghoshal.medium.com/how-lithium-ion-batteries-in-evs-catch-fire-9d166c5b3af1 

Guo, F., Ozaki, Y., Nishimura, K., Hashimoto, N., & Fujita, O. (2020). Influence of lithium salts on the combustion characteristics of dimethyl carbonate-based electrolytes using a wick combustion method. Combustion and Flame, 213, 314–321. https://doi.org/10.1016/j.combustflame.2019.12.001 

Larsson, F., Andersson, P., Blomqvist, P., & Mellander, B. (2017). Toxic fluoride gas emissions from lithium-ion battery fires. Scientific Reports, 7(1). https://doi.org/10.1038/s41598-017-09784-z 

Schoenfisch, M., & Dasgupta, A. (2022, September). Grid-Scale Storage – Analysis – IEA. IEA. https://www.iea.org/reports/grid-scale-storage 

Zhang, L., Duan, Q., Meng, X., Jin, K., Xu, J., Sun, J., & Wang, Q. (2022). Experimental investigation on intermittent spray cooling and toxic hazards of lithium-ion battery thermal runaway. Energy Conversion and Management, 252, 115091. https://doi.org/10.1016/j.enconman.2021.115091