为什么钠离子不用铜箔做负极集流体？

Why don't sodium ions use copper foil as the anode current collector?    

钠离子电池不采用铜箔做负极集流体，核心原因是铝箔在钠电池电解液体系中稳定性远超铜箔，且性能完全满足需求，性价比更高。在钠离子专属电解液环境中，铝箔表面会形成一层致密稳定的钝化膜，不会发生腐蚀、氧化、溶解现象，能够长期稳定承载钠离子嵌脱和电流传导，完全适配负极工作需求。反观铜箔，不仅采购价格远高于铝箔、生产成本更高，在钠电池工作工况下，还容易出现微量氧化、腐蚀问题，长期循环会影响电池稳定性。因此钠电池摒弃了锂电池的铜箔负极方案，全铝箔集流体设计成为其降本核心优势。

The core reason why Sodium-ion Battery does not use copper foil as the anode current collector is that aluminum foil has much better stability than copper foil in the sodium battery electrolyte system, and its performance fully meets the demand with higher cost performance. In the sodium-specific electrolyte environment, a dense and stable passivation film will be formed on the surface of aluminum foil, which will not corrode, oxidize or dissolve, and can stably carry the sodium ion intercalation and deintercalation and current conduction for a long time, which fully adapts to the working demand of the anode. On the contrary, copper foil not only has a much higher purchase price than aluminum foil and higher production cost, but also is prone to slight oxidation and corrosion problems under the working conditions of sodium batteries, which will affect the battery stability during long-term cycling. Therefore, sodium batteries have abandoned the copper foil anode scheme of lithium batteries, and the all-aluminum foil current collector design has become its core cost reduction advantage.