钠离子电池和钠离子电容器的核心区别是什么？

What are the core differences between sodium-ion batteries and sodium-ion capacitors?

二者混合体系与纯电池体系，储能机理、密度、循环各有不同。一储能机理：钠电池完全依靠正负极离子嵌入脱出电化学反应；钠电容为混合体系，负极硬碳离子嵌入、正极碳材料双电层物理吸附，兼顾电容与电池特性。二能量密度：纯钠电池 120~160Wh/kg；钠电容 60~100Wh/kg，介于超级电容与钠电池之间。三功率密度：钠电容瞬时大功率放电性能远超普通钠电池，适合短时脉冲工况。四循环寿命：钠电池 3000~6000 次；钠电容可达数万次，耐频繁启停冲击。五自放电：钠电容自放电高于常规钠电池，长期静置亏电更快。六充放电区间：钠电容倍率范围更广，5C~10C 快充无明显极化；普通钠电池高倍率压降显著。七成本：同等容量钠电池造价更低；同等峰值功率钠电容更有优势。八应用场景：钠电池户储、长时光伏；钠电容地铁制动、港口机械脉冲供电、短时大功率应急电源。九 BMS 管控：钠电容压差波动更大，均衡系统精度要求更高。

They are pure battery and hybrid systems with distinctions in storage mechanism, density and cycle life. 1. Storage principle: Sodium-ion batteries fully rely on electrochemical ion intercalation on cathodes/anodes; sodium-ion capacitors are hybrid systems combining hard carbon ion intercalation anodes and double-layer physical adsorption carbon cathodes with dual capacitor & battery features. 2. Energy density: Pure sodium cells 120~160 Wh/kg; sodium capacitors 60~100 Wh, between supercapacitors and sodium batteries. 3. Power density: Sodium capacitors deliver far superior instantaneous high-power discharge for short pulse loads. 4. Cycle life: Sodium batteries 3,000~6,000 cycles; sodium capacitors reach tens of thousands of cycles resisting frequent start-stop shocks. 5. Self-discharge: Sodium capacitors self-discharge faster than conventional sodium cells with quicker power loss during long standby. 6. Rate performance: Sodium capacitors support 5C~10C fast charging without severe polarization; ordinary sodium cells suffer large voltage drop under high rates. 7. Cost: Sodium batteries cost less at equal capacity; capacitors gain advantages at equal peak power. 8. Scenarios: Sodium batteries for household storage and long-duration PV; sodium capacitors for subway braking, port machinery pulse power and short high-power emergency supplies. 9. BMS control: Sodium capacitors generate larger voltage fluctuations requiring higher balancing precision.