Na2Li2Ti6O14 is synthesized by a simple solid state method between 500 and 900°C. It is found that pure Na2Li2Ti6O14 is only formed at 800°C or above. The tap density of as-prepared Na2Li2Ti6O14 is about 1.52gcm−3. Particle morphology analysis shows that the size of Na2Li2Ti6O14 gradually increases with the increase of sintering temperature. Calcined at 900°C, Na2Li2Ti6O14 shows slight particle aggregation and melting. As a result, Na2Li2Ti6O14 formed at 800°C reveals higher electrochemical activity than the sample obtained at 900°C. Therefore, the suitable preparation temperature for Na2Li2Ti6O14 by solid state reaction is 800°C. Charge–discharge results show that Na2Li2Ti6O14 prepared at 800°C can deliver a reversible capacity of 89.9mAhg−1 at 100mA g−1, 81.3mAhg−1 at 200mAg−1, 75.2mAhg−1 at 300mAg−1, 69.6mAhg−1 at 400mAg−1 and 65.5mAhg−1 at 500mAg−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.