Safe and fast-charging Li-ion battery with long shelf life for power applications

We report a Li-ion battery that can be charged within few minutes, passes the safety tests, and has a very long shelf life. The active materials are nanoparticles of LiFePO4 (LFP) and Li4Ti5O12 (LTO) for the positive and negative electrodes, respectively. The LiFePO4 particles are covered with 2 wt.% carbon to optimize the electrical conductivity, but not the Li4Ti5O12 particles. The electrolyte is the usual carbonate solvent. The binder is a water-soluble elastomer. The 18650 battery prepared under such conditions delivers a capacity of 800 mAh. It retains full capacity after 20,000 cycles performed at charge rate 10C (6 min), discharge rate 5C (12 min), and retains 95% capacity after 30,000 cycles at charge rate 15C (4 mn) and discharge rate 5C both at 100% DOD and 100% SOC. (C) 2010 Elsevier B.V. All rights reserved.