The growing market appeal of rechargeable lithium-ion batteries (LIBs) for booming electric vehicles and portable electronics as well as the high cost and scarcity of lithium are driving research to develop alternatives to LIBs. Sodium-ion batteries (SIBs) has thus emerged and attracted considerable scientific and industrial interests as a promising potential alternative to LIBs with great economic benefits, which mainly attributes to the low cost and natural abundance of sodium. Briefly, SIBs is believed to be able to offer savings of around 30 percent in terms of cost per kWh of LIBs, mostly because of sodium's lower cost (sodium ⁓ 600 US$/ton vs. lithium ⁓ 24,000 US$/ton) and natural abundance (Na 23,600 ppm vs. Li 20 ppm). Moreover, SIBs shares many similar characteristics with LIBs, from charge storage mechanism to cell structure, thus facilitate the production of SIBs with the available LIBs production technique and equipment. Currently, the key challenge is how to improve the performance of SIB enough to widely commercialize it. Based on the prototype of rechargeable coin cell SIBs with high energy density and supercapacitor-like power density that was achieved within ERC “ThreeDSurface” project, the ERC Proof of Concept project “HiNaPc” is accordingly struggle to further develop pouch cells of SIBs with high energy and power density, and pave the way toward establishing a production-scalable process for mass production of pouch cell SIBs through upscaling coin cell SIBs, thus enabling the battery manufacturers to further develop and produce full SIBs system for electric vehicles and portable electronics. In this “HiNaPc” project, a pouch cell SIBs has been successfully realized with large-scale nanorod arrays as anodes (mainly antimony) and P2-Na2/3Ni1/3Mn2/3O2 nanoparticles as cathodes. The pouch cell SIBs can be operated at 3.2 V which is similar to that of some commercial LIBs. The energy capacity of the pouch cell SIBs in this project reaches higher than 30 Ah and the cost is lower than US$ 200 per kWh. Meanwhile, it has good rate capability and long-termed cycling stability up to 300 cycles. More importantly, the developed production process for assembling pouch cell SIBs is almost exactly the same with that of the commercial pouch cell LIBs, including all the necessary equipment. Obviously, the significant achievements within “HiNaPc” project will certainly accelerate the practical process of pouch cell SIBs, and it is believed that cost-effective pouch cell SIBs will come to market in the near future.
