钠电池单体和电池包有什么区别？

Does Sodium-ion Battery need a protection board?    

钠电池单体和电池包是完全不同的层级产品，属于基础单元与集成成品的关系。钠电池单体是电池的最小独立单元，由正负极、电解液、隔膜、外壳封装而成，具备基础的储放电能力，但电压、容量有限，无法直接满足大功率设备使用需求。电池包是系统集成成品，由数十上百个钠电池单体通过串联、并联组合排布，同时搭配BMS电池管理系统、散热系统、绝缘防护结构、密封外壳、线束组件组装而成。单体负责基础储能，电池包负责智能管控、稳定输出、安全防护，是直接面向终端用户的成品，广泛用于电动车、储能电站等场景。

Sodium-ion Battery must be used with a protection board (BMS Battery Management System), which is indispensable. Sodium batteries without protection boards are strictly prohibited from being put into use directly. The core function of the protection board is to comprehensively protect the safety and service life of the battery, which can real-time and accurately monitor the core data such as voltage, current, temperature and pressure difference of the battery cell and battery pack, and intelligently control the charge and discharge process. When abnormal conditions such as overcharge, over discharge, over current, short circuit, high temperature and excessive monomer pressure difference occur, the protection board will automatically cut off the circuit to avoid risks such as thermal runaway, swelling, short circuit and burning. At the same time, it can correct the monomer power difference through the equalization function, improve the overall consistency and cycle life of the battery pack, and is the core guarantee for the safe and stable operation of the sodium battery.