Zeyu Ma

Butler–Volmer-Equation-Based Electrical Model for High-Power Lithium Titanate Batteries Used in Electric Vehicles

The lithium titanate battery, which uses Li4Ti5O12 (LTO) as its anode instead of graphite, is a promising candidate for fast charging and power assist vehicular applications due to its attractive battery performance in rate characteristics and chemical stability. Unfortunately, commonly used battery models, including a large number of enhanced electrical models, become problematic when describing current-voltage characteristics of lithium titanate batteries. In this paper, a novel Butler-Volmer equation-based electric model is employed to outline unique phenomena induced by changing rates for high-power lithium titanate batteries. The robustness of the proposed model for three types of lithium titanate batteries under varying loading conditions, including galvanostatic test and Federal Urban Dynamic Schedule test, is evaluated and compared against experimental data. The experimental results of three types of lithium titanate batteries with common anode materials but differentiated cathode materials show good agreement with the model estimation results with maximum voltage errors below 2%.

Research on Parallel Characteristics of Lithium Iron Phosphate Batteries for Dual Electric Multiple Units

The performance of power lithium ion battery pack in parallel will be further degraded due to the inconsistency of the cells. Under different working conditions, battery pack in parallel reflects different charging and discharging characteristics. In this paper, based on the series-parallel simulation platform, the actual current of parallel battery pack was obtained from the power characteristic of dual electric multiple unit (DEMU). The charging and discharging characteristics of parallel connection for Lithium iron phosphate (LiFePO4) battery batteries with constant current and the loop current phenomenon under different state of charge (SOC) were investigated combined with the practical charging and discharging tests in the laboratory, which are helpful to get the main causes of aging of battery pack in parallel. An optimized usage range of SOC is proposed which provides the basis for battery management and prolongs the battery life cycle.

The Design of Traction Power Battery System for Dual Power Urban Rail Metro

Combined with traction and braking characteristics of urban rail metro and the analysis of the battery system demand, which is in traction power of dual power urban rail metro, the energy and power demand of traction power battery system in the dual power urban rail metro is determined, through the simulation and calculation of the specific line condition of the Beijing Western Suburbs. Taking the energy and power demand, the axle load limit and installation size restriction into account, the battery system configuration is certain with the selection of lithium–titanate battery. Besides, the feasibility of battery selection and configuration is verified by calculation and analysis.

Research on Applicability of Lithium Titanate Battery for Low-Floor Vehicles

Based on the application characteristics of lithium battery for low-floor vehicles, lithium titanate battery has advantages of application over other types of lithium batteries. The reasonable test scheme of lithium titanate battery can be formulated on the basis of existing test platform of single battery. Rate characteristics and low temperature characteristics of lithium titanate battery can be obtained through charge and discharge tests of two lithium titanate batteries at different temperatures and rates. Combined with characteristics of lithium titanate battery and operation characteristics of low-floor vehicles, the applicability of lithium titanate battery for low-floor vehicles is analyzed.