Suspensions of natural graphite particles were prepared in an aqueous medium using carboxymethyl cellulose ͑CMC͒ and emulsified styrene-butadiene copolymer latex as part of an environmentally friendly fabrication process for graphite anodes ͑negative electrodes͒ intended for application in Li-ion batteries. Suspensions were characterized by adsorption isotherms, electroacoustic measurements, rheology and sedimentation tests, at two different degrees of carboxymethyl substitution ͑DS͒ on CMC. A lower DS value ͑0.7͒ resulted in greater uptake of CMC on graphite compared with a higher DS value ͑1.28͒. This was attributed to attractive hydrophobic interactions associated with the lower carboxymethyl substitution. The greater adsorption for DS = 0.7 correlates with lower relative viscosity in concentrated graphite suspensions, a higher adhesion strength with a copper substrate, and a greater retention of discharge capacity after cycling. The effect of DS is attributed to differences in the aqueous dispersion properties and stability of graphite suspensions. Based on these results, we fabricated high-capacity graphite negative electrodes characterized by gravimetric and volumetric energy densities of greater than 340 mAh/g and 560 mAh/cm 3 , respectively. This formulation also led to improved adhesion strength, giving the as-fabricated cell an attractive cycle life greater than 90% of initial discharge capacity after 200 cycles.

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A carbon-free Li(4)Ti(5)O(12) electrode has shown excellent electrochemical performance without any effort to enhance the electrical conductivity. Partial reduction of Ti(4+) and a metallic Li(7)Ti(5)O(12) phase are suggested to be possible origins of the exceptional behavior.

Germanium holds great potential as an anode material for lithium ion batteries due to its large theoretical energy density and excellent intrinsic properties related to its kinetics associated with lithium and electrons. However, the problem related to the tremendous volume change of Ge during cycling is the dominant obstacle for its practical use. The previous research has focused on the improvement in mechanics associated with lithium without consideration of the kinetics. In this study, we demonstrate that the configuration engineering of the Ge electrode enables the improvement in kinetics as well as favorable mechanics. Two types of Ge inverse opal structures with porous walls and dense walls were prepared using a confined convective assembly method and by adjusting Ge deposition parameters in a chemical vapor deposition system. The Ge inverse opal electrode with porous walls shows much improved electrochemical performances, especially cycle performance and rate capability, than the electrode with dense walls. These improvements are attributed to a large free surface, which offers a facile strain relaxation pathway and a large lithium flux from the electrolyte to the active material.

Despite the great achievement in understanding the materials properties and powder engineering of LiFePO 4 , the chemical bonding at the surface has been almost ignored. Herein, we demonstrate that the undercoordinated Fe 2+ /Fe 3+ redox couple at the surface gives a high barrier for charge transfer, but it can be stabilized by nitrogen or sulfur adsorption. The surface modification improves greatly the charge transfer kinetics and the charge/discharge performance of a LiFePO 4 cathode. Density functional theory (DFT) calculation estimates the origin of the improvement in terms of an electronic and ionic contribution based on a surface model probed by time of flight secondary ion mass spectrometry (TOF-SIMS); the calculation agrees well with an experimental rate-constant analysis.