Na2Li2Ti6O14 is synthesized by a simple solid state method between 500 and 900 degrees C. It is found that pure Na2Li2Ti6O14 is only formed at 800 degrees C or above. The tap density of as-prepared Na2Li2Ti6O14 is about 1.52 g cm(-3). Particle morphology analysis shows that the size of Na2Li2Ti6O14 gradually increases with the increase of sintering temperature. Calcined at 900 degrees C, Na2Li2Ti6O14 shows slight particle aggregation and melting. As a result, Na2Li2Ti6O14 formed at 800 degrees C reveals higher electrochemical activity than the sample obtained at 900 degrees C. Therefore, the suitable preparation temperature for Na2Li2Ti6O14 by solid state reaction is 800 degrees C. Charge-discharge results show that Na2Li2Ti6O14 prepared at 800 degrees C can deliver a reversible capacity of 89.9 mAh g(-1) at 100 mA g(-1), 81.3 mAh g(-1) at 200 mA g(-1), 75.2 mAh g(-1) at 300 mA g(-1), 69.6 mAh g(-1) at 400 mA g(-1) and 65.5 mAh g(-1) at 500 mA g(-1). Besides, the lithium storage mechanism in Na2Li2Ti6O14 is also studied by various in-situ and ex-situ methods, which prove that the structural evolution is highly reversible for Na2Li2Ti6O14 during lithiation/delithiation process. (C)2015 Elsevier Ltd. All rights reserved.