For the first time, Cu(NO3)2·xH2O (x ≤ 2.5) is investigated as a new lithium storage anode material for lithium-ion batteries. The impressive characteristic of Cu(NO3)2·xH2O(x ≤ 2.5)/Li cell is the high initial discharge capacity reaching to around 2200 mAh g−1. To make a comparison, Cu(NO3)2·2.5H2O electrodes are used as raw materials and heat-treated at 80, 120 and 160 °C. Among all the three samples, Cu(NO3)2·xH2O (x < 2.5) obtained at 160 °C shows the highest reversible capacity of 597.6 mAh g−1 and the best cycling stability after 30 cycles. The difference in electrochemical behaviors is attributed to the variation of surface morphology, crystal water and particles size after heat-treatment at different temperatures. Besides, the thermal reaction results also show that Cu(NO3)2·xH2O (x < 2.5) obtained at 160 °C has the highest thermal stability among all the three samples after repeated cycles. The present findings can provide the fact that Cu(NO3)2·xH2O (≤2.5) may be a promising anode material for lithium-ion batteries.