The aim of the invention is to provide novel electrolyte additives to enhance the performance of Li ion batteries. Using 4-chloromethyl-1,3,2-dioxathiolane,2-oxide as an additive, the co-intercalation of PC and the subsequent exfoliation of graphite anode can be suppressed and this provides a safer cell for low temperature application of lithium ion battery. In addition, 1,3,2-dioxathiolane,2-oxide with different halo and/or haloalkyl substituent groups can have high reduction potential resulting in the formation of protecting layer on electrode. Such novel electrolyte additives can minimize the capacity loss and improve the poor cycle ability of lithium ion battery for different electrolyte compositions. Another aim of the invention is to provide novel electrolyte additives to improve the performance of anode materials such as graphite and Si-based anode materials in lithium ion battery. A further aim of the invention is to improve the performance of cathode materials such as LiCoO2 and Li-excess layered oxide cathode materials in lithium ion battery. The inventors have found that based on experimental and quantum chemical calculations, a serious of additives containing sulfur and halogen functional groups that are effective to improve the performance of lithium ion battery.
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