基于集流内阻解耦模型的锂离子液流电池研究

Lithium-ion flow battery is the recently-developed electrochemical battery technology, which has a good application prospect in the field of grid energy storage. How to reduce the battery internal resistance and to improve the energy density and efficiency through the innovative design, is in present the technical bottleneck of the lithium-ion flow battery. For this reason, an idea of collection resistance decoupling is put forward to decouple the relationship between the reaction channel size and the battery internal resistance. According to this model, we change the existing battery structure to design the new lithium-ion flow battery. The preliminary test result is very promising. Therefore, it is necessary to establish the quantitative collection resistance decoupling model for analyzing the reaction mechanism and process of the new structure battery, and for figuring out the spatial distribution of the charges in the electrode suspensions. In combine with the fluid mechanics simulation and the experiment results, it's planned to get the optical best match relationship between the current rate, the electrode slurry flow rate and the reaction channel size, to guide the modification of the porous collectors and the optimal design of the sandwich composite layers, and finally to improve the energy efficiency and energy density of the battery. The research work will provide the scientific basis and the possible-breakthrough direction for solving the technical bottleneck problem. As a result, a number of independent intellectual properties will be achieved for the industrial application of the lithium-ion flow battery in the future.

锂离子液流电池是最近发展起来的一种化学储能电池，在电网储能领域应用前景良好。如何通过创新设计降低电池内阻，提高电池能量密度和能量效率，是目前锂离子液流电池基础研发阶段有待突破的技术瓶颈。为此，申请人提出集流内阻解耦的模型思路，改变现有电池的结构设计，从原理上将电池反应腔大小和电池集流内阻解耦，设计并制作新型锂离子液流电池，初步试验效果明显。研究工作将建立定量的集流内阻解耦模型，结合流体力学仿真与模拟，研究新型结构电池的电化学反应机理和过程，弄清楚电极悬浮液荷电状态的空间分布规律，探讨电池倍率特性与电极悬浮液流速和反应腔大小之间的最佳匹配关系，并指导多孔集流层的改性处理和夹心复合结构层的优化设计，提高电池能量密度和能量效率，为上述技术瓶颈问题的解决提供科学依据和创新的突破方向。研究工作将获得一批具有自主知识产权的原始创新成果，为今后锂离子液流电池的规模应用及产业化发展奠定基础。

锂离子液流电池是一种新型电化学储能技术，本项目从复合电极浆料制备及性能优化、集流内阻解耦结构模型建立与仿真模拟、夹心复合结构层设计与改性制备、电池反应器优化设计及液路循环系统搭建测试四部分对其展开了研究。取得的代表性成果如下：（1）获得了悬浮稳定性较好，且能量密度较高的复合电极浆料制备方法；（2）建立了基于集流内阻解耦结构的新型电池电化学模型和流体动力学模型，获得了不同电池设计参数、流速、驱动时间等对电池性能的影响规律；（3）通过夹心复合结构层特征参数模拟、材料筛选及表面改性、复合结构设计，获得了性能较好的夹心复合结构层，作为电池反应器核心部件；（4）设计加工了不同容量和功率等级的电池反应器，并设计搭建了电池液路循环的软硬件系统，成功实现了电池系统的液路循环功能;（5）电池在太阳能路灯系统（12V/30W/1.3kWh）和低速电动车系统（48V/800W/1.6kWh）中开展了成功的实况测试及试应用。在项目资助下，发表学术论文15篇，申请国家发明专利19项，获授权7项，并建立了1400平米的产学研中试研究基地，实现了电池由实验室性能验证到中试生产及示范应用的突破，还发展了30余人的研究团队，为该技术方向的进一步研究及放大生产奠定了基础。