RESEARCH ARTICLE Turning an environmental problem into an opportunity: potential use of biochar derived from a harmful marine biomass named Cladophora glomerata as anode electrode for Li-ion batteries Pejman Salimi 1 & Soheila Javadian 1 & Omid Norouzi 2 & Hussein Gharibi 1 Received: 9 April 2017 /Accepted: 11 September 2017 # Springer-Verlag GmbH Germany 2017 Abstract The electrochemical performance of lithium ion battery was enhanced by using biochar derived from Cladophora glomerata (C. glomerata) as widespread green macroalgae in most areas of the Iran’ s Caspian sea coast. By the utilization of the structure of the biochar, micro-/macro- ordered porous carbon with olive-shaped structure was suc- cessfully achieved through pyrolysis at 500 °C, which is the optimal temperature for biofuel production, and was activated with HCl. The biochar and HCl treatment biochar (HTB) were applied as anode electrode in lithium ion batteries. Then, elec- trochemical measurements were conducted on the electrodes via galvanostatic charge–discharge, cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS) analyses. The electrochemical results indicated a higher specific dis- charge capacity (700 mAh g -1 ) and good cycling stability for HTB at the current density of 0.1 A g -1 as compared to the biochar. The reason that HTB electrode works better than the biochar could be due to the higher surface area, formation functional groups, removal impurities, and formation some micropores after HCl treatment. The biochar derived from marine biomass and treatment process developed here could provide a promising path for the low-cost, renewable, and environmentally friendly electrode materials. Keywords Biochar . Carbon . HCl treatment . Lithium-ion batteries . Anode . Environmentally friendly Introduction Among all energy storage devices, Li-ion batteries (LIBs) have attracted increasing attention for portable electronic devices and transportation applications because of their obvious advantages including high energy density, good rate performance, reliable stability, and long lifespan (Javadian et al. 2016; Gul et al. 2014; Wang et al. 2016). To date, a few carbon-based materials, such as carbon nanotubes, and graphene have been investigated as battery electrodes (Jin et al. 2014). Unfortunately, due to their low-energy density, high cost of processing the materials, and negative environmental impacts, the application of these materials has been limited to comparatively small markets (Yu et al. 2016; Zheng et al. 2014; Hong et al. 2016). Considering the demand for renewable sources of energy, more and more attention has been focused on ther- mochemical processes (e.g., pyrolysis and hydrothermal gasification) to convert biomass to biofuel and valuable chemicals such as phenol, acetic acid, and furfural (Qu et al. 2015). Biochar is one of the by-products of the py- rolysis process which is often considered as a soil amend- ment, water treatment, activated carbon production, and catalyst support (Ren et al. 2014). Recently, extensive re- search has been carried out on the biochar derived from biomass to find a promising alternative source of carbon- based material which is low cost and environmentally friendly (Kalyani and Anitha 2013). Various types of bio- chars, particularly those derived from terrestrial biomass, Responsible editor: Bingcai Pan * Soheila Javadian javadian_s@modares.ac.ir; javadians@yahoo.com 1 Department of Physical Chemistry, Faculty of Science, Tarbiat Modares University, PO Box 14115-175, Tehran, Iran 2 School of Chemistry, College of Science, University of Tehran, Tehran, Iran Environ Sci Pollut Res DOI 10.1007/s11356-017-0181-1