为使用低污染的方法制备低温可膨胀石墨（LTEG），以天然鳞片石墨（NFG）为原料，以高氯酸溶液为电解液，通过电化学法制备了起始膨胀温度低，低温膨胀容积大且不含硫的LTEG。探讨了电流密度、电解时间、电解液中HClO4的质量分数和膨胀温度对膨胀容积（EV）的影响，采用FTIR、TGA和XRD对制得的LTEG进行了研究。结果表明：电解液中HClO4的质量分数可以低至50%，与化学法相比大幅降低，电解液易于循环使用，对环保有利；LTEG在200 ℃和950 ℃时的EV分别高达282 mL/g和594 mL/g，具有高倍率、无硫和低温膨胀性能；LTEG表面有羰基和羧基生成，层间存在ClO4－和HClO4插层物；在2θ为25.76 º处的特征衍射峰强度非常弱，而在2θ为9.41 º处有一宽峰，对应层间距为0.941 nm；在60～330 ℃之间发生明显热失重，失重率约28%，在60～800 ℃之间的总热失重率约35%。

In order to obtain the low-temperature expandable graphite (LTEG) by means of a low pollution method, the natural flake graphite (NFG) was oxidized in the perchloric acid solution by means of the electrochemical method. Thus, the sulfur-free LTEG of a large exfoliated volume (EV) and a low initial exfoliating temperature was prepared. Then, the influences of the current density, the electrolysis time, the mass fraction of HClO4 in electrolyte and the exfoliating temperature on the EV were discussed, and the LTEG was characterized by means of FTIR, TGA and XRD. The results show that (1) the mass fraction of HClO4 in electrolyte can be as low as 50%, which dramatically decreases in comparison with the results of chemical oxidation methods; (2) recycling the electrolyte is easy, which helps to reduce environmental pollution; (3) the EV of the LTEG reaches up to 282 mL/g and 594 mL/g respectively at the exfoliating temperatures of 200 ℃ and 950 ℃, and the LTEG is high-rate, sulfur-free and expandable at low temperatures; (4) there exists  carbonyl and carboxyl on the surface of the LTEG, and there exists ClO4－ and HClO4 as intercalation compounds within the space between the graphite pieces; (5) the intensity of the characteristic diffraction peak at a 2θ of 25.76 º is very weak, and a broad peak appears at a 2θ of 9.41 º with an interlayer distance of 0.94 nm; and (6) the thermal weight loss of the LTEG occurs obviously between 60～330 ℃ with a thermal weight loss rate of about 28%, and the total thermal weight loss rate is about 35% between 60～800 ℃.