Developments and developing trends of lithium-ion batteries (LIBs) are summarized first: it is proposed that solid thin film microbatteries and large-scale all-solid-state rechargeable LIBs are the two main developing tendencies. Meanwhile, cost and safety issues are the primary limitations to improve advanced LIBs with excellent electrochemical performance. Next, one of the most promising cathode materials, LiFePO4, is introduced in detail. Advantages and drawbacks of LiFePO4 as cathode active material are analyzed, then, main approaches to circumvent its drawbacks proposed by many groups are also summarized. In addition, some mechanism investigations on this cathode material presently and challenging problems waiting for solutions before LiFePO4 can be commercialized are also discussed in this review.