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Why do V-shaped ball valves used as lithium battery cathode materials require that the valve body be prohibited from containing zinc and copper? The core is to prevent trace metal impurities from contaminating the cathode powder, avoid battery self-discharge, internal short circuit, and thermal runaway, while ensuring cycle life and production yield. 1. How impurities enter the battery ball valve body, valve core, seals, and fasteners. If copper/zinc is contained, wear or corrosion will release metal particles/ions, which will be mixed with positive electrode powders such as lithium iron phosphate and ternary. The positive electrode material manufacturing process (mixing, sintering, transportation, coating) cannot effectively remove copper/zinc, and electromagnetic iron removal is ineffective for non-magnetic Cu/Zn. 2. Fatal effects on the battery: dendrite short circuit and thermal runaway (the most dangerous). When the battery is charged, Cu²⁺/Zn²⁺ is reduced to metal dendrites at the negative electrode, and the sharp dendrites pierce the separator, causing an internal short circuit. ； It can range from severe self-discharge to severe thermal runaway, fire and explosion. Performance is greatly attenuated, internal resistance rises, and capacity dives.: Impurities destroy the crystal structure of the cathode, hinder lithium ion conduction, shorten the cycle life by 30%+, and increase the self-discharge rate by 5 times. Aggravation of side effects: Cu/Zn catalyzes the decomposition of the electrolyte, produces gas and bulges, further deteriorating the consistency and safety of the battery. Yield and cost disaster Trace impurities (ppm level) can lead to batch scrapping ； Leading companies lose tens of millions of dollars annually due to Cu/Zn contamination, and rework costs are 3–5 times the production cost. 3. Mandatory requirements for ball valve materials: valve body/valve core: 316L stainless steel, duplex steel (2205/2507), titanium, Hastelloy or full ceramic, absolutely free of Cu/Zn. Seals/Fasteners: Non-metals such as PTFE, PPL, UHMWPE, or copper-zinc-free stainless steel to prevent contact contamination. Ban copper and zinc on all links: The actuator, solenoid valve, limit switch, and coating must be Cu/Zn-free to avoid secondary pollution. 4. Industry Standards and Regulations National Standard GB/T 31241-2014: The concentration of Cu/Zn in workshop air is <0.5 μg/m³. EUREACH: Cu/Zn inclusion * * Substances of Very High Concern (SVHC) * * Restrictions list. It can be seen from the above that copper and zinc are "highly toxic impurities" in lithium batteries. Therefore, banning zinc from copper valves and ball valve body materials blocks pollution from the source and ensures battery safety, performance and yield.