The utilization of CO in Li-CO batteries is attracting extensive attention. However, the poor rechargeability and low applied current density have remained the Achilles' heel of this energy device. The gel polymer electrolyte (GPE), which is composed of a polymer matrix filled with tetraglyme-based liquid electrolyte, was used to fabricate a rechargeable Li-CO battery with a carbon nanotube-based gas electrode. The discharge product of Li CO formed in the GPE-based Li-CO battery exhibits a particle-shaped morphology with poor crystallinity, which is different from the contiguous polymer-like and crystalline discharge product in conventional Li-CO battery using a liquid electrolyte. Accordingly, the GPE-based battery shows much improved electrochemical performance. The achieved cycle life (60 cycles) and rate capability (maximum applied current density of 500 mA g ) are much higher than most of previous reports, which points a new way to develop high-performance Li-CO batteries.

Lithium-ion batteries (LIBs) are being used to power the commercial electric vehicles (EVs). However, the charge/discharge rate and life of current LIBs still cannot satisfy the further development of EVs. Furthermore, the poor low-temperature performance of LIBs limits their application in cold climates and high altitude areas. Herein, a simple prelithiation method is developed to fabricate a new LIB. In this strategy, a Li V (PO ) cathode and a pristine hard carbon anode are used to form a primary cell, and the initial Li extraction from Li V (PO ) is used to prelithiate the hard carbon. Then, the self-formed Li V (PO ) cathode and prelithiated hard carbon anode are used to form a 4 V LIB. The LIB exhibits a maximum energy density of 208.3 Wh kg , a maximum power density of 8291 W kg and a long life of 2000 cycles. When operated at -40 °C, the LIB can keep 67 % capacity of room temperature, which is much better than conventional LIBs.

The utilization of CO 2 in Li-CO 2 batteries is attracting extensive attention. However,the poor rechargeability and lowapplied current density have remained the Achilles heel of this energy device.The gel polymer electrolyte (GPE), which is composed of apolymer matrix filled with tetraglymebased liquid electrolyte,w as used to fabricate ar echargeable Li-CO 2 battery with ac arbon nanotube-based gas electrode. The discharge product of Li 2 CO 3 formed in the GPE-based Li-CO 2 battery exhibits ap article-shaped morphology with poor crystallinity,w hichi sd ifferent from the contiguous polymer-like and crystalline discharge product in conventional Li-CO 2 battery using al iquid electrolyte.A ccordingly,t he GPE-based battery shows much improved electrochemical performance.T he achieved cycle life (60 cycles) and rate capability (maximum applied current density of 500 mA g À1 ) are muchh igher than most of previous reports,w hichp oints anew way to develop high-performance Li-CO 2 batteries.