Toward Low-Cost All-Organic and Biodegradable Li-Ion Batteries

Abstract

this work presents an alternative method for fabricating Li-ion electrodes in which the use of aluminum/copper current collectors and expensive binders is avoided. Low-cost natural cellulose fibers with a 2-mm length are employed as binder and support for the electrode. The objective of this method is to eliminate the use of heavy and inactive current collector foils as substrates and to replace conventional costly binders with cellulose fibers. Moreover, no harmful solvents, such as N-methylpyrrolidone, are employed for film fabrication. Water-soluble carbons are also utilized to reduce the preparation time and to achieve a better repartition of carbon in the electrode, thus improving the electrochemical performance. flexible and resistant Lifepo 4 (Lfp), Li 4 ti 5 o 12 (Lto), organic 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA), and graphite electrodes are obtained with active mass loadings similar to those obtained by the current casting method. The initial discharge capacity of approximately 130 mAh•g −1 at 2 C is obtained for an LFP/LTO paper battery with an approximately 91.6% capacity retention after 1000 cycles. An all-organic prelithiated PTCDA/graphite cell without a transition metal is prepared and electrochemically tested. It is one of the first selfstanding batteries that is composed of organic redox active molecules and biodegradable components reported in literature. Over the past decade, flexible electronics 1,2 have undergone rapid developments in the fields of wearable 3,4 and implantable devices 5 , flexible displays 6 , and even flexible radio frequency identification tags 7. Li-ion battery is the most developed energy supply technology that satisfies high demands in energy, power, and long cycle life 8,9. For these reasons, flexible Li-ion batteries have gained particular attention as a future energy storage solution for lightweight and flexible devices 10,11. The widely used method for fabricating Li-ion electrodes (i.e., web-coating method), however, is unable to adequately satisfy these requirements 12. In fact, Cu and Al metal foils, which are generally used as current collector and support to spread the cathode or anode ink, lose contact with the active material during repeated bending 13. Moreover, the conventional method usually employs costly binders (such as polyvinylidene fluoride (PVDF)) that are dissolved in solvents (e.g., N-methyl-2-pyrrolidone (NMP)), which are characterized by high toxicity 14. Drying such electrodes also consumes a significant amount of energy because of their high boiling point (204.3 °C) and low vapor pressure (e.g., 1 mm Hg at 40 °C for NMP) 15. A greener process that employs sodium carboxymethyl cellulose as a low-cost binder and water as solvent has been reported 16-18 ; however, some major problems have to be resolved. Water-based electrodes exhibit agglomeration effects, poor ink homogeneity, and residual moisture after drying, which considerably reduce the cycle life of the battery 19. According to the cost modeling proposed by Wood et al. 20 ...

Becoming Sustainable, The New Frontier in Soft Robotics

“…Delaporte et al recently reported on a flexible Li-ion battery that utilizes cellulose fibers as binder and support for the electrode and active materials when mixed with different carbons or redox active materials (such as LiFePO 4 (LFP), Li 4 Ti 5 O 12 (LTO), or organic 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA)). [144] Their best battery achieved a capacity of 160 mAh g −1 (without encapsulation) with LTO electrodes and about 80 mAh g −1 with PTCDA electrodes.…”

A low-cost and Li-rich organic coating on a Li4Ti5O12anode material enabling Li-ion battery cycling at subzero temperatures

“…In addition, PTCDA is a semiconducting material. 46,47 For these reasons, the coating of LTO particles with PTCLi 4 was of interest to yield a material with a good surface conduction of Li-ions and electrons. In addition, the thin PTCLi 4 layer can provide overcharge protection in a full-cell configuration, as its redox potential is lower than that of LTO.…”

Facile formulation and fabrication of the cathode using a self-lithiated carbon for all-solid-state batteries

“…The modified carbon is first dispersed in deionized water to obtain a perfect and homogeneous suspension, as shown in Fig. 2 a,b, for CNT–COOH 38 . Further, an excess NMC (99 or 99.5 wt% of the total solid mass) is added to the solution and mixed thoroughly.…”

“…Synthesis of water-soluble carbons: VGCF-COOH and CNT-COOH. The modification procedure was adapted from a recent work 38 . 5 g of carbon (VGCF or CNT, see Fig.…”