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

We propose a innovative concept to boost the electrochemical performance of cathode composite electrodes using surface-modified carbons with hydrophilic moieties to increase their dispersion in a Lithium Nickel Manganese Cobalt Oxide (NMC) cathode and in-situ generate Li-rich carbon surfaces. Using a rapid aqueous process, the hydrophilic carbon is effectively dispersed in NMC particles followed by the conversion of its acid surface groups (e.g. -COOH), which interact with the NMC particles due to their basicity, into grafted Li salt (-COO-Li+). The solid-state batteries prepared using the cathode composites with surface-modified carbon exhibit better electrochemical performance. Such modified carbons led to a better electronic conduction path as well as facilitating Li+ ions transfer at the carbon/NMC interface due to the presence of lithiated carboxylate groups on their surface.

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

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 LiFePO4 (LFP), Li4Ti5O12 (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 self-standing batteries that is composed of organic redox active molecules and biodegradable components reported in literature.