A sodium-ion battery is a rechargeable battery that uses sodium ions as charge carriers. Its working principle is close to that of a lithium-ion battery, but its electrode materials and supply chain are different. In October 2026, signals that sodium-ion batteries are moving from laboratory and pilot lines toward mass production became clear: according to reports, LG Energy Solution's Nanjing Plant 1 line is being converted into a sodium-ion pilot line with annual capacity of about 200 MWh, while CBAK Energy signed a sodium-ion battery project in the Gaochun Economic Development Zone, Nanjing, on September 23, with planned annual capacity of 12 GWh covering large cylindrical 60150 sodium-ion cells and integrated systems, plus a 6 GWh expansion at its existing Nanjing plant planned before the end of 2026. As these projects land, tab welding becomes a step no mass-production line can skip.
1. Why do sodium-ion production lines deserve attention?
Interest in sodium-ion batteries starts with cost and resources: sodium is more widely distributed and generally easier to source than lithium, which makes sodium batteries a useful complement to lithium batteries in energy storage and some power applications. The second factor is the pace of scale-up: pilot lines and gigawatt-hour-scale projects are appearing at the same time, which suggests sodium batteries are leaving the sample stage and entering a phase where stable output and yield must be proven. For equipment suppliers, the signal is not any single company's project but the combination of pilot, expansion and overseas plants — Peak Energy in the United States is also building what it describes as the country's first sodium-ion grid storage factory in Sacramento, California, with planned annual capacity of 4 GWh, production targeted for the first quarter of 2027, and more than 6 GWh of customer orders already claimed.
2. How is sodium battery tab welding different from lithium battery tab welding?
From a welding point of view, the similarities outweigh the differences: both need a reliable connection between tabs, current collectors and busbars, and welds must withstand current, vibration and long-term cycling. Differences mainly come from material and stack combinations: tab materials, thicknesses and layer structures can vary between manufacturers, so welding parameters cannot simply be copied from a lithium battery line. The safer approach is to treat each sodium battery design as a welding case to be re-validated: confirm the tab material and stack structure first, then run welding trials, rather than fixing the machine model first.
3. What should buyers check when choosing an ultrasonic power battery welding machine?
An ultrasonic power battery welding machine joins metals through high-frequency vibration friction. The process generally produces no sparks and needs no solder, and it suits stacked welding of thin copper, aluminium and other non-ferrous metals. Four checks matter most: first, weld strength and consistency — the smaller the pull-force variation within a batch, the lower the reliability risk after cells are grouped; second, weld appearance and tab damage — welding should not pierce the tab or damage its coating; third, cycle time — machine output should match the line with some headroom; fourth, changeover — when several tab sizes share one line, die change and parameter adjustment time directly affect uptime.
4. How should a buyer proceed, step by step?
Step one is to supply real samples: weld with the actual tab material and actual stack structure, and check pull force, weld appearance and consistency. Step two is small-batch validation: weld a continuous batch and look at the spread, not only the best single result. Step three is to discuss capacity fit and after-sales support, including spare parts, process commissioning and operator training. This article covers no order or tender information, and project timelines should be confirmed against later company announcements. If you are selecting tab welding equipment for a sodium-ion battery line, feel free to contact Shanghai Jingjin for a free welding sample test.