锂离子电池储能电柜使用水灭火产氢分析研究

Analysis and research on hydrogen production from using water to extinguish the energy storage cabinet of lithium-ion batteries

“双碳”目标的提出给我国锂电储能行业发展带来了新机遇,随之而来的储能电柜热失控问题也日渐凸显。消防水由于兼具易得性、有效性及经济性三大属性,成为处置锂离子电池火灾最常规的手段,但应对高压储能电柜火灾时电解产氢的问题使其安全性受到质疑。本工作在广泛调研的基础上,采用理论分析及定量计算的方法建立了不同边界情况下储能电柜电解产氢速率及产氢浓度的模型,以此探究利用不同水质处置储能电柜热失控方案的安全性。结果表明:(1)储能电柜电解产氢速率受多种因素影响。其中,电化学参数对产氢速率的影响很小,而水质电导率、电柜绝缘保护及电解温度等对产氢速率影响较大,是影响产氢速率的关键因素;(2)以市场上主流的两种预制舱式储能集装箱为例,在极端条件下(水温为90℃;内部所有储能电柜浸水,电柜及电箱绝缘保护均被破坏;内部通风失效,无通风):(1)使用自来水水质灭火时,持续3 h,其氢气浓度仍远小于爆炸下限,具备灭火可行性;(2)使用海水水质灭火时,持续1 h,其氢气浓度小于爆炸下限,配合通风措施,具备灭火可行性;(3)使用工业碱水水质(30%KOH溶液)灭火时,产生的氢气浓度会大于爆炸下限,安全风险较大。

The proposal of the dual-carbon goal brought new opportunities to the development of China's lithium-ion energy storage industry.Correspondingly,the thermal runaway problem of energy storage cabinets became increasingly prominent.Due to its three major attributes of accessibility,effectiveness,and economy,firewater is considered as the most common solution to lithium-ion battery fires.However,the safety of its usage is questioned due to the issue of electrolytic hydrogen production in response to high-voltage energy storage cabinet fires.On the basis of extensive research,this study adopts theoretical analysis and quantitative calculation methods to establish models for the electrolytic hydrogen production rate and the energy storage cabinet concentration under different boundary conditions to explore the safety of using different water qualities to dispose of the thermal runaway schemes of the energy storage cabinets.The results indicate that the electrolytic hydrogen production rate of the energy storage cabinets is influenced by various factors.As the key factors affecting the hydrogen production rate,the electrochemical parameters only slightly affect the hydrogen production rate,while the water conductivity,electrical cabinet insulation protection,and electrolysis temperature significantly affect it.In this work,two mainstream prefabricated energy storage containers in the market are taken as examples.Under extreme conditions(i.e.,90 ℃ water temperature),the energy storage cabinets were completely submerged;the insulation protection of the cabinets and boxes was damaged;and internal ventilation failed.According to the results,when tap water is used for fire extinguishment,the hydrogen concentration remains far below the lower explosion limit for 3 h,indicating the feasibility of fire termination.Seawater used for the same purpose lasts for 1 h,with the hydrogen concentration being less than the lower explosion limit.Fire extinguishment using seawater is feasible when using ventilation measures.Lastly,when industrial-quality alkaline water(30% KOH solution) is used,the generated hydrogen concentration is greater than the lower explosion limit,posing a significant safety risk.