Battery Technology

Battery Technology 


The power battery system is one of the most core parts for the electromobile. Thus, it is a key step to select corresponding battery systems and set up a reasonable battery system in developing the electromobile in good performance. And how does Jiangsu MIN'AN EV make the key step?

Based on different vehicle models, MIN'AN EV selects different battery cells integrated with designed driving mileage, power performance, safety performance, market orientation, and other comprehensive factors to build distinctive power battery systems.

 

Battery cell is the foundation of power battery in the electromobile.

Currently, the power battery accessible to commercialized application in electromobile including lead-acid battery, NI-MH battery, lithium iron phosphate battery, ternary lithium battery, multi-component lithium battery, lithium titanate battery, etc. with the comparison of key performance parameters in batteries made of different materials as follows:

  

Battery   Type

Energy   Density

Cycle   Life

Rate   Capability

Security  

Efficiency  

Lead-acid   battery

35Wh/kg

<   500 times

Good  

High  

Good  

NI-MH   battery

80   Wh/kg

<   500 times

Good  

Common  

Poor  

Ternary   battery

150-180   Wh/kg

300-1,000   times

Common  

Common  

Common  

Lithium   iron phosphate battery

90-110   Wh/kg

>   2,000 times

Good  

High  

Common  

Multi-component   lithium battery

70-200   Wh/kg

300-1,500   times

/

/

Poor  

Lithium   titanate battery

60-80   Wh/kg

>   5,000 times

Very   good

High  

Poor  


Batteries made of different material have their own advantages and shortcomings. And the most popular battery material system currently is the ternary lithium material. MIN'AN EV also advocates for the ternary lithium material system which can be applied to multiple vehicle models thanks to its high voltage platform, high energy density, and perfect low-temperature performance. 

Battery management system is the brain and neural network in the power battery system of the electromobile.

Adoption of good battery cells is just a good foundation for setting up a power battery system and the management of batteries in charging and discharging is the key technology in battery application. By adopting fully independently developed battery management system (hereinafter referred to as BMS - Battery Management System) and Kalman filtering algorithm, MIN'AN EV realizes accurate SOC estimation, realizes real-time monitoring of voltage, current, temperature and other parameter information of the power battery by adopting master-slave chip design, ensures consistency of battery packs and prolongs service life of battery packs equipped with the function of large-current active equalization, realizes real-time remote monitoring of battery data by GPRS module, and realizes thermal equilibrium management of the battery system via BMS master plate or the dry contact of slave plate. 

Thermal management system is the health management expert in the power battery system of the electromobile. 

Thermal management is another key technology in the power battery system. The service life of batteries will be effectively prolonged by thermal equilibrium management of battery systems, reducing and even avoiding thermal runaway and other extreme safety accidents. There are multiple ways of thermal management in the power battery system with such common methods as natural cooling, ventilation and cooling/heating, liquid cooling/heating, phase-change material heat conduction. MIN'AN EV primarily adopts natural cooling and liquid cooling/heating or liquid steeping to realize thermal equilibrium management of battery systems. Then, concerning different vehicle models, how to draw ways of thermal management? Set up mathematic model to conduct hydromechanical and thermodynamic analysis, design a reasonable liquid flow pipeline aided by proper fluid drive equipment (water pump, etc.) and conduct design verification on the project in line with design ideas, targeting on different vehicle models and the placement of the battery system combined with charging and discharging conditions of the battery system in all kinds of operating conditions, which will eventually guarantee the temperature range of the battery system in all kinds of operating conditions is lower than 8℃.