Applications on ships

1、 Technical principles and system composition
The core application of energy storage batteries on ships lies in the storage and release of electrical energy through electrochemical reactions. Its system composition mainly includes battery packs, battery management systems (BMS), and electric propulsion devices:

Battery pack: composed of multiple battery cells connected in series or parallel to provide the electrical energy required by the ship. Common types include lithium-ion batteries (such as lithium iron phosphate batteries, ternary lithium batteries), lead-acid batteries, etc. Among them, lithium-ion batteries have become the mainstream choice due to their advantages such as high energy density and long cycle life.
Battery Management System (BMS): responsible for real-time monitoring of parameters such as voltage, temperature, and current of the battery pack, ensuring that the battery pack operates within a safe range, and extending battery life through balanced management.
Electric propulsion device: converts the stored electrical energy in the battery into mechanical energy to drive the rotation of the ship's propeller. Propulsion motors usually use permanent magnet synchronous motors or asynchronous motors, which have the characteristics of high efficiency and low noise.
In addition, to improve system performance, ship energy storage systems often use composite power technology, such as parallel connection of supercapacitors and lithium batteries. Supercapacitors have characteristics such as high power density and fast charging and discharging, which can effectively cope with instantaneous high-power demands such as ship start-up and acceleration, while lithium batteries are responsible for providing continuous and stable power output.

2、 Application scenarios and requirement analysis
According to the different types of ships and navigation requirements, the application scenarios of energy storage batteries can be subdivided into the following categories:

Inland vessels: mainly consisting of inland ferries and tourist passenger ships, with high requirements for zero emissions and low noise. The energy storage system can completely replace traditional diesel engines, achieve pure electric navigation, and meet urban environmental protection needs.
Offshore vessels: such as port operation ships, fishing boats, etc., with relatively fixed operating ranges, can use shore power for charging. Combining energy storage systems with shore power can optimize energy allocation and reduce operating costs.
Ocean going vessels require extremely high energy density, stability, and reliability of energy storage systems to meet the demands of long-term and long-distance navigation. The current research focuses on improving the energy density of lithium batteries and developing new energy storage technologies, such as fuel cells.
Special vessels: including research ships, engineering ships, etc. The energy storage system needs to provide stable power for high-precision equipment and have the ability to cope with complex sea conditions.

3、 Advantages and Challenges
Advantages:
Environmental friendliness: Zero emission or low emission operation, significantly reducing greenhouse gas and pollutant emissions.
Economy: Reduce fuel consumption and maintenance costs, improve operational efficiency.
Energy efficiency improvement: By utilizing energy recovery technologies such as brake energy recovery, energy utilization efficiency can be further enhanced.
Operational flexibility: The electric propulsion system has a fast response speed, making it easy to achieve precise control.
Challenge:
High initial cost: The cost of high-performance battery packs and BMS is relatively high, which increases the investment in ship construction.
Insufficient charging infrastructure: The layout of shore power facilities and charging stations is not yet perfect, which affects the widespread application of energy storage systems.
Technical bottleneck: Battery energy density, cycle life, and safety still need to be improved to meet the long-distance needs of ocean going vessels.
Lack of standards and regulations: The lack of unified technical standards and safety regulations for ship energy storage systems hinders industrial development.